Spatial patterns of density at multiple life stages in protected and fished conditions: An example from a Mediterranean coastal fish

    Spatial patterns of density at multiple life stages in protected and fished conditions: An example from a Mediterranean coastal fish A. Di Franco, M. Di Lorenzo, P. Guidetti PII: DOI: Reference:

S1385-1101(12)00197-9 doi: 10.1016/j.seares.2012.11.006 SEARES 1025

To appear in:

Journal of Sea Research

Received date: Revised date: Accepted date:

2 December 2011 9 November 2012 30 November 2012

Please cite this article as: Di Franco, A., Di Lorenzo, M., Guidetti, P., Spatial patterns of density at multiple life stages in protected and fished conditions: An example from a Mediterranean coastal fish, Journal of Sea Research (2012), doi: 10.1016/j.seares.2012.11.006

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ACCEPTED MANUSCRIPT Spatial patterns of density at multiple life stages in protected and

Laboratory of Conservation and Management of Marine and Coastal

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A. Di Franco1,2*, M. Di Lorenzo1, P. Guidetti1,2

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fished conditions: An example from a Mediterranean coastal fish

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Resources, DiSTeBA, University of Salento, 73100 Lecce, Italy Université de Nice Sophia-Antipolis, Faculté des Sciences, EA 4228 ECOMERS,

F-06108 Nice cedex 2, France

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*Corresponding author. Tel.: +390832298885: fax: +390832298626. E-

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mail address: [email protected] (Antonio Di Franco)

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Running head: Spatial patterns of fish within and outside MPAs

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Keywords: Settlement, recruitment, Marine Protected Areas, coastal fish, Mediterranean

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ACCEPTED MANUSCRIPT Abstract

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Settlement and recruitment are well known to have critical influences on the

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demography of most marine fishes. Few studies have compared processes like larval supply, settlement and recruitment of fishes between protected (i.e. in

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Marine Protected Areas, MPAs) and unprotected conditions and little

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information is available about the potential influence of early life history traits (e.g. pelagic larval duration, PLD) on these processes. In the present study, using the white sea bream Diplodus sargus sargus as a model species in the south-western Adriatic Sea, we investigated: 1) potential differences in the

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densities of adults, settlers, recruits and 1-YOs (one year old specimens) within an MPA and in unprotected areas, at multiple spatial scales; 2) the

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existence of local relationships between densities of adults (i.e. spawners),

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settlers, recruits and 1-YOs; 3) the possible relationships between PLD and density of settlers. Both in 2009 and 2010 the density of settlers was higher at

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sites down-current to the MPA and showed a significant variability at the scale of sites (kms). Density of recruits only revealed variability among sites (both in 2009 and 2010), while density of 1-YOs was variable at the scale of sites and was higher in protected condition in 2011, but not in 2010. No significant relationships were found between the densities of adults, settlers, recruits and 1-YOs at the site scale, nor between PLD and the density of settlers. Results suggest a possible decoupling in space between the sequential life history stages of fish (from settlers to 1-YOs) due to dispersal (through sea currents or active fish movements). Further study may help better understand the 2

ACCEPTED MANUSCRIPT actual contribution of MPAs to larval supply and recruitment in both MPAs and

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adjacent sites.

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ACCEPTED MANUSCRIPT 1. Introduction

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Most coastal fishes are characterized by complex life cycles containing several

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potentially highly dispersive pelagic phases (i.e. eggs and larvae, but see Almany et al., 2007; Swearer et al., 1999), followed by relatively site-attached

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(i.e. nectobenthic) juvenile and adult phases. The transition from the

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planktonic to the benthic habitats, termed „settlement‟ (the time when an individual takes up permanent residence in the demersal habitat, Levin, 1994), usually coincides with the metamorphosis of larvae into juveniles (Kingsford, 1988). After a period, variable in duration depending on the species

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(Macpherson, 1998), juveniles join the adult fraction of the population, during a phase named „recruitment‟ (Forrester, 1990).

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The number of settlers in a given spatial unit (e.g. a stretch of coast) is

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influenced by pre-settlement (e.g. dispersal and mortality of eggs and larvae in the plankton, larval behavior; Fontes et al., 2009; Pelc et al., 2010; Schmitt

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and Holbrook, 2002; Sponaugle et al., 2003) and early post-settlement events (site/habitat selection at settlement, competition, predation, food availability, shelter availability and patterns of movement; Beets, 1997; Bussotti and Guidetti, 2011; Hixon and Carr, 1997), which ultimately affect the distribution patterns of juveniles (Adams and Blewett, 2004). Intensity of settlement has been also related to early life history traits (e.g. pelagic larval duration, larval growth, size at settlement) in a number of papers that, however, provided quite contrasting evidence (see Fontes et al., 2010 and Fontes et al., 2011). The “stage duration” hypothesis states that mortality at settlement (e.g. due to 4

ACCEPTED MANUSCRIPT predation and starvation) increases as PLD increases (Legget and Deblois, 1994) and from this perspective a negative relationship could be expected

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between average PLD and the density of settlers at the same site. From this

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perspective, PLD could potentially affect densities at successive life stages. Both settlement and recruitment may have critical influences on fish population

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size and demography (Carr and Syms, 2006; Cheminee et al., 2011; Doherty

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and Fowler, 1994; Fontes et al., 2009), influencing population renewal in time, shaping the structure of fish assemblages (Cheminée et al., 2011; Sano, 1997) and, in the case of commercial fishes, replenishing the exploitable stocks (Mapstone and Fowler, 1988; Victor, 1986 but see Forrester, 1990). In

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general, however, the roles that pre-settlement, at settlement and postsettlement processes play in shaping patterns of fish distributions remain

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poorly known for most marine species (Raventos, 2009).

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The intensity of settlement and recruitment can be related to the ability of spawners to produce offspring. Marine protected areas (MPAs), by enhancing

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breeding stock biomass (Roberts and Polunin, 1991), may boost egg production via local increases of abundance and size of spawners (Evans et al., 2008; Guidetti et al., 2011). Both egg and larval retention and export can take place depending on a number of features, like larval behavior, oceanography, etc. (Pelc et al., 2010). In the case of local larval retention and very limited post-settlement movements, higher settlement and recruitment rates are expected to take place locally within MPAs (Bohnsack and Ault, 1996; Valles et al., 2001).

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ACCEPTED MANUSCRIPT Very few studies have compared spatial distribution patterns of settlers, recruits and 1-YOs between MPAs and unprotected areas (Grorud-Colvert and

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Sponaugle, 2009; Valles et al., 2001; Vigliola et al., 1998), especially for the

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Mediterranean region. The scant information does not allow the importance of retention to be differentiated from the dispersal mechanisms (i.e. evaluating

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patterns at settlement), or of the spatial relationships between the different life

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stages of fish (i.e. assessing potential relationships in terms of the spatial patterns of density among successive life stages) and, on the whole, the actual contribution of MPAs to replenishment of local fish populations. For both conservation and management targets it is a priority to investigate

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the relationships between egg/larval production, settlement and recruitment (Cheminée et al., 2011). For marine organisms, a complete understanding of

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population dynamics would require a thorough consideration of both settlement

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and recruitment patterns at multiple spatial and temporal scales (Forrester, 1990; Schmitt and Holbrook, 1999, 2002).

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So far, most studies have examined either subsets of life stages (e.g., larvae to early juvenile, juvenile to adult, e.g. Valles et al., 2001), general processes (e.g., larval supply, post-settlement mortality, e.g. Macpherson et al., 1997) or specific mechanisms (e.g., predation, Hixon and Carr, 1997), very often at a single spatial scale. Studies that simultaneously considered multiple life stages across multiple spatial scales are rare. Using the white sea bream D. sargus sargus as a model species in the southwestern Adriatic Sea, the aim of the present study, therefore, was to investigate 1) the potential differences in the distribution of adults (spawners), 6

ACCEPTED MANUSCRIPT settlers, recruits and 1-YOs within an MPA and in unprotected areas, at multiple spatial scales; 2) the relationships between the densities of adults (i.e.

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spawners), settlers, recruits and 1-YOs at local (kms) scale; 3) the

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relationships between pelagic larval duration (PLD) and settlement magnitude.

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2.1 Study area and species

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2. Materials and Methods

This study was carried out along ~200 km of the Apulian Adriatic Coast (southwestern Adriatic Sea, Italy). The circulation pattern of the Southern Adriatic

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Sea, where the study area is located, is characterized by a current (the Western Adriatic Coastal Current or WACC) flowing southward along the coast

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(Oddo et al., 2005).Three stretches of coast, hereinafter named „geographic

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directions‟ (GD) were identified: North (from Bari to the Torre Guaceto MPA northern boundary), Torre Guaceto MPA (hereinafter TGMPA) and South (from

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TGMPA southern boundary to Otranto). Within North and South directions, and within the TGMPA, six sites and two sites, respectively, were randomly selected (Fig. 1) from a larger set of sites. The number of sites within each GD was determined depending on the length of the coastline (i.e. no more than two sites were available within TGMPA). The study area is characterized by a rocky plateau with a gentle to medium slope, decliningfrom the water surface to a depth of ~10-12 m over coarse sand and Posidonia oceanica beds (Guidetti, 2006). Coralligenous formations develop at deeper stands (>25-30 m). 7

ACCEPTED MANUSCRIPT TGMPA was formally established in 1991, but enforcement only became effective around 2000-2001. The entire TGMPA covers 2227 ha, extends along

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about 8 km of coastline, and is subdivided into three zones: (1) a no-take and

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no-access reserve (Zone A, according to Italian law, 179 ha); (2) a general reserve zone (Zone B, 163 ha) and (3) a partial reserve, formally a buffer zone

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(Zone C, 1885 ha). In Zone B only coastal recreational non-extractive activity

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(i.e. swimming) is allowed. In Zone C, artisanal (professional) fishing is allowed, restricted to stands deeper than 10 m and to a small number of vessels (≤8) authorized to fish once per week. In Zone C strictly regulated recreational fishing is allowed under severe restrictions (i.e. maximum catch in

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weight, periods, types of baits allowed and number of authorizations/day released) and spearfishing is totally banned. Due to the restrictions enforced,

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fishing activity does not target juvenile and sub-adult fishes within TGMPA. Any

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effects of fishing on these individuals, therefore, can be reasonably excluded. On the whole, due to the reduced fishing pressure in fishable areas within

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TGMPA, no potential differences were expected among different zones within TGMPA (also supported by the authors unpublished data) especially within the depth range sampled. All sites investigated within TGMPA (i.e. site TGMPA1, located at the border between zone B and zone C, and site TGMPA2 located within Zone A) were therefore classified as belonging to the same protection level. The TGMPA is effectively enforced and recent studies reported higher densities and sizes of many coastal fishes compared to those in adjacent fished areas (Guidetti, 2006; Guidetti et al., 2008). Based on this, the TGMPA can be 8

ACCEPTED MANUSCRIPT considered as a potentially more effective spawning area and, therefore, source of propagules (eggs and larvae) compared to fished areas outside.

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The white sea bream Diplodus sargus sargus (Linnaeus, 1758) is an

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ecologically (Guidetti, 2006) and economically relevant coastal species (for both professional and recreational fishing, Lloret et al., 2008). It is widely

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distributed in the Mediterranean, Eastern Atlantic and Black Seas (Froese and

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Pauly, 2011). This fish, that clearly responds to protection from fishing by increasing in density and in size (Di Franco et al., 2009; Guidetti and Sala, 2007), usually inhabits the littoral zone in shallow waters down to about 50 m (Harmelin-Vivien et al., 1995; Tortonese, 1965).

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Adults are relatively sedentary (D‟Anna et al., 2011; Lino et al., 2009 for studies carried out on artificial reefs, Abecasis et al., 2009 in lagoons and Di

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Lorenzo et al., unpublished in a Mediterranean MPA) and demersal, and

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produce eggs and larvae that develop in pelagic waters for a period ranging from 14 to 28 days (Di Franco and Guidetti, 2011; Di Franco et al., 2011;

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Vigliola, 1998). After the metamorphosis, settlers of about 1.0-1.5 cm in size (Macpherson, 1998) thrive in shallow (<2 m depth) coastal benthic habitats mainly represented by small bays with mixed sand and rocks (Harmelin-Vivien et al., 1995; Tortonese, 1965). Juveniles recruit when they reach approximately 6-7 cm in size, ~5-6 months after settlement (Macpherson, 1998). One year after the settlement individuals reach a size between 10 cm and 15 cm TL (data from the same area derived from otolith ageing; Guidetti et al. unpublished).

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ACCEPTED MANUSCRIPT In the study area, due to the characteristics of distribution of coastal habitats (see description above), adults of white sea bream are mainly associated with

2.2 Sampling design and data collection

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shallow rocky bottoms, within 10-12 m in depth.

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The densities of white sea bream at different life stages (i.e. settlers, recruits,

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1-YO specimens, adults) were assessed by means of the underwater visual census (UVC) method within and outside TGMPA, in 2009 and 2010 for settlers and recruits, 2010 and 2011 for 1-YOs and 2010 for adults. Adults (i.e. spawners) were identified as all being D. sargus sargus specimens >18 cm TL

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(corresponding to the size at first maturity, Mouine et al., 2007). For each life stage, sampling years were chosen in order to follow the same cohort from

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settlement to 1-YO in two subsequent years. A single sampling year was

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chosen for adults to provide an overall picture of the adult fraction of the population and as a proxy for spawning potential.

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Density of settlers and recruits was evaluated along strip transects of 25 × 2 m (Bussotti and Guidetti, 2011; Harmelin-Vivien et al., 1985). Sampling of settlers was carried out parallel to the coastline, in small embayments hosting shallow (i.e. 0-2 meters) rocky habitats alternated with sandy patches. These habitats are considered the preferred habitat for D. sargus sargus settlers (Harmelin-Vivien et al., 1995; Tortonese, 1965 and Bussotti and Guidetti, 2011 for evidence from the TGMPA). Sampling sites were randomly selected out of a pool of possible sites having similar features in terms of habitat types‟ coverage, availability of refuges (i.e. small crevices and crannies) and 10

ACCEPTED MANUSCRIPT exposure. Sixteen and 8 random transects were carried out in each site for settlers and recruits, respectively. The number of replicate transects in each

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site for each life stages was set after exploratory surveys and related to fish

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distribution patterns (i.e. highly aggregated for settlers requiring a higher number of replicates).

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Density of settlers was assessed during (or shortly after) the settlement peaks

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at the beginning of June 2009 and at the end of June 2010. The occurrence of settlement peaks was identified by means of repeated censuses conducted every ~3-4 days at 4-5 multiple sites per day (randomly selected and interspersed among GDs) each sampling year. When the peak was detected,

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sampling was started and performed at all the sampling sites (sampled once in each year) within 5 days to reduce temporal variability in the data set.

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Sampling dates at each site within the 5 days temporal window of the sampling

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campaign were temporally interspersed among the three GDs. Interspersion of sampling units in space and time is considered to be an obligatory feature of

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good sampling designs helping avoid confounded sampling design (sensu Underwood, 1997) and biased data sets (Hurlbert, 1984). As an additional a posteriori precaution, we assessed the relationship between settlement date (estimated through otolith analyses, Di Franco and Guidetti unpublished data) and density at the 14 sites, which is expected to be significant in the case of spatio-temporal confounding in estimating settlement rate. Settlement date per site and average density of settlers per site were not significantly related (2nd order polynomial regression test, p=0.81).

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ACCEPTED MANUSCRIPT Density of recruits was estimated between 2 and 4 m depth, respectively in October 2009 and November 2010, corresponding to the period of recruitment

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peak (Macpherson, 1998).

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Densities of 1-YOs and adult specimens were sampled using 8 strip transects of 25 × 5 m (Harmelin-Vivien et al., 1985), in each site at a depth between 6-

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10 m.

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In each transect, abundance and size (total length, TL, recorded within 2 cm size classes) of 1-YOs and adults encountered were recorded. In this study, all D. sargus sargus comprised between 10 cm and 15 cm TL were defined as 1YOs based on the „total length vs age‟ relationships derived from otolith ageing

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(Guidetti et al. unpublished data). The 1-YOs in 2010 were from the same annual cohort of settlers censused in 2009. For all life stages, each transect

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was run in about 10 min, using a tape of pre-established length (i.e. 25 m).

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The actual numbers of fish encountered were recorded up to 10 individuals, whereas for larger groups, categories of abundance were used (i.e. 11–30, 31–

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50, 51–200, 201–500, >500 ind.; see Harmelin-Vivien et al., 1985). When data were recorded as a category of abundance, the average fish abundance was calculated taking into account the midpoint of each category.

2.3 Data analyses To test for potential differences in densities of settlers, recruits, 1-YOs and adults between TGMPA and unprotected areas north and south of TGMPA, the permutational analysis of variance (PERMANOVA) on square root transformed data was used. Geographical Direction (GD, three levels: North, MPA and 12

ACCEPTED MANUSCRIPT South) was treated as a fixed factor, Site (Si, two levels in MPA and six levels in North and South) was treated as a random factor nested in GD. Separate

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analyses were performed for each of the two sampling years and „year‟ was not

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considered as a formal factor to exclude any potential dependence of replicates in time (possible spatial overlapping of replicates across years for each life

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stage considered). For settlers, 16 replicates per site and direction were used

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(n=224 per sampling year); for recruits, 1-YOs and adults 8 replicates per site and direction (n=112 for each of the three life stages per sampling year). Total sampling effort thus equaled 784 replicated visual census transects. Post-hoc pairwise tests were run, whenever appropriate, after PERMANOVA detected

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significant differences. Data were tested for homogeneity of dispersion among levels of Geographic Directions using Permutational Analysis of Multivariate

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Dispersions (PERMDISP) based on Euclidean distance, which is equivalent to

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Levene‟s test for heterogeneity of variances when used on univariate data (Anderson et al., 2008).

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To test for potential differences in the sizes of adults (positively related to egg/larval production) among the different GDs and to avoid any assumption about the distribution of the variable, the 1-way PERMANOVA was used. Individual fish size data were pooled for each GD, plotted as size–frequency distributions and analyzed by comparing average size among the 3 GDs. Linear regression analyses (DISTLM) were used to assess the relationships between the different life stages examined (i.e. settlers, recruits, 1-YOs and adults), and between settlers and previously published PLD values (these latter referred only to 2009 samples and were assessed from otoliths extracted from 13

ACCEPTED MANUSCRIPT individuals sampled at the same 14 sampling sites selected for density assessments). For each site and year, an average of the replicates was

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considered. All the values were expressed as the number of ind./m2. DISTLM

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was employed to test, in detail, 1) the relationship between adult (i.e. spawners) population density and “successful” larval output (using density of

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early settlers as a proxy for successful larvae and not focusing on total larval

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output, potentially subject to several sources of larval mortality) for one of the two sampling years (i.e. 2010 when density of both adults and settlers was assessed), 2) the relationships between density of settlers and density of recruits in each of the two years, 3) the relationships between density of

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recruits and density of 1-YOs (belonging to the same cohort) in both years, and 4) the relationship between PLD values (from Di Franco and Guidetti, 2011

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referred to the same 14 sampling sites in 2009) and density of settlers in

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2009.

package.

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Statistical analyses were run using the Primer 6 PERMANOVA + software

3. Results

PERMANOVA analysis on density data of adults provided evidence of a significant difference between levels of GD (tab. 1): pairwise tests (p<0.05 for both tests) highlighted that the density recorded within TGMPA was 10 to 20 times higher than in both northern and southern unprotected locations 14

ACCEPTED MANUSCRIPT (respectively, 1.6±0.6 ind./125 m2 mean±S.E. in the TGMPA vs 0.14±0.12 and 0.08±0.04 ind./125 m2 outside, Fig. 2). Significant differences were detected

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at the scale of sites (tab. 1). PERMDISP detected difference in dispersion

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(p<0.05) with MPA≠North=South (p<0.05 for both pairwise tests). From this

both to a location and dispersion effect.

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perspective difference among TGMPA and North and South could be attributed

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Size distributions showed significant differences among GDs, with bigger fish sizes observed in the TGMPA, and no differences recorded between South and North sectors (pairwise test p<0.05; Fig. 3).

The densities of settlers significantly differed among levels of GD both in 2009

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and in 2010 (tab. 2): during 2009 TGMPA and southern sites showed values similar to each other and 5-10 times higher than the values recorded in

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northern sites (for both pairwise tests: p<0.01; Fig. 2); during 2010 the

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highest values were recorded in southern sites, with density at TGMPA statistically comparable to that at northern sites (for both pairwise tests:

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p<0.05; Fig. 2). Significant variability at the scale of sites was recorded both in 2009 and 2010. PERMDISP did not highlight heterogeneity of dispersions in 2009 nor in 2010 data. In both sampling years, no differences were recorded in the density of recruits in relation to the factor GD, while a significant variability was detected at the scale of sites (tab. 2). PERMDISP did not highlight heterogeneity of dispersions in 2009 nor in 2010 data. As a general rule, visual inspection of the graph clearly showed that average density of recruits in 2010 was about 5-fold less

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ACCEPTED MANUSCRIPT than in 2009 (Fig. 2). Within the South GD, site 4 showed the lowest density of settlers and the highest density of recruits both in 2009 and 2010.

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Density of 1-YOs significantly differed among levels of GD only in 2011 with

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highest values recorded within TGMPA (tab 1; for both pairwise tests: p<0.05). This output was mainly driven by the high values recorded just in one of the

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two protected sites (Fig. 2). A significant variability at the spatial scale of sites

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was recorded in both 2010 and 2011. A clear inter-annual variability can be observed with densities in 2011 far lower than densities in 2010. PERMDISP did not highlight heterogeneity of dispersions in 2009 nor in 2010 data. No significant relationships (p>0.05) were recorded between the density of the

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different life stages investigated: i.e. settler vs recruit density/m2 per site in both 2009 and 2010; recruit vs 1-YO density/m2 per site in both 2009-2010

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and 2010-2011; spawner vs settler density/m2 per site in 2010 (n=14; fig 4).

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No relationships were recorded between PLD and density of settlers (p>0.05;

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fig. 5).

4. Discussion

The present study did not detect any locally-related effects of protection on the distribution patterns of settlers and recruits of white sea bream in the southern Adriatic Sea. Contrasting evidence emerged for 1-YO specimens in the two sampling years. Adult fish were more abundant and larger inside the investigated MPA compared to fished areas outside, but this pattern was not mirrored in local density patterns of settlers and recruits. These findings, which 16

ACCEPTED MANUSCRIPT agree with the little evidence available in the literature (Grorud-Colvert and Sponaugle, 2009; Vigliola et al., 1998), do not mean that protection provided

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by the MPA does not produce any effect, beside the positive effect on density

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and size of adult fish hosted inside. More abundant and larger spawners within the TGMPA (Guidetti, 2006; this study) could enhance local eggs and larval

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production (Guidetti et al., 2011 for a study at TGMPA; but see Evans et al.,

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2008 for another case study), but the effects in terms of settler arrival could reverberate elsewhere, due to an export of propagules. More specifically, propagules could be exported southwards, according to the direction of dominant currents in the study area (Artegiani et al., 1997) that directionally

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disperse eggs and larvae (sensu Pelc et al., 2010). Considering propagules (i.e. eggs and larvae) as passive particles dispersed by sea currents, modeling

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evidence highlights that eggs/larval dispersal of Diplodus sargus sargus can

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occur over about 100-200 km (Di Franco et al., submitted). This process could connect the highest settlement found at southern sites with the high potential

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of propagule production within TGMPA. However, it has to be stressed that both larval behavior (Leis et al., 2011) and habitat selection (Grorud-Colvert and Sponaugle, 2009) can play a role in determining patterns of density at settlement. This spatial decoupling or mismatch could be further confirmed by the absence of significant local relationships between density of spawners and settlers in this study. A positive relationship between density of spawners and larvae and/or post-larvae, instead, could arise in MPAs located in areas characterized by the presence of oceanographic features (e.g. eddies) enhancing larval 17

ACCEPTED MANUSCRIPT retention (see Crechriou et al., 2010 for a Mediterranean case study) and consequently self-recruitment. As far as we know no information is currently

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available about the magnitude of larval retention and/or larval export for

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Diplodus sargus sargus and further studies (i.e. implying genetic and/or Lagrangian simulations) are required to shed light on this crucial point.

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Moreover it has to be considered that MPA size could affect the probability of

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retention and/or export of propagules locally produced, with larger MPAs potentially able to enhance the chance that larvae settle within their natal MPA (Botsford et al. 2009; Hasting and Botsford 2006). In the present study, general decoupling between adults and settlers could be also due to the

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relatively small size of TGMPA.

Besides sea currents, spatial patterns at settlement are likely to be influenced

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by a wide array of other pre-settlement events, as well as differential habitat-

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specific post-settlement early mortality (i.e. during the first hours after settlement), and/or microhabitat selection (Grorud-Colvert and Sponaugle,

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2009; Schmitt and Holbrook, 2002). This variety of processes could explain the variability we have detected at the scale of sites (even though we selected sampling sites as similar as possible in terms of habitat type, and sampled to correspond with the settlement peak in order to minimize temporal bias), a general feature that was also reported in other studies (Valles et al., 2001; Vigliola et al., 1998). Potential differences in microhabitats could help explain some specific patterns like the one recorded in the southern site number 4 (low settlement and high recruitment magnitude) and the high differences recorded among the two sites investigated within TGMPA. 18

ACCEPTED MANUSCRIPT No significant relationships were found between PLD and densities of settlers. This outcome, therefore, does not support the “stage duration” hypothesis. The

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lack of relationship between PLD and settlers density is more likely in cases of

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low variability in average PLD among sites (Fontes et al., 2011); this evidence could be explanatory for findings of the present study where the PLD was

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significantly different at small scale (i.e. 6-8 km), but not at a larger scale (i.e.

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30 km, Di Franco and Guidetti, 2011). From this perspective, it could be hypothesized that the directional effect of sea currents could be the major determinant of settlement patterns at TGMPA and in the flanking areas for the white sea bream Diplodus sargus sargus. Further specific studies are needed to

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better address this issue and therefore this statement should be considered cautiously.

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Spatial patterns of settlers were not related to those of recruits or 1-YOs. This

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could be due to multiple mechanisms, such as post-settlement mortality (Machperson, 1997), but also to active juvenile movements that may cause

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spatial rearrangements of fish density at and after settlement (Di Franco et al., 2012). The causes of post-settler mortality are not yet fully clarified although some studies showed that predation may seriously affect mortality rates of early “benthic” stages of fish (e.g. Connell, 1997; Hixon and Carr, 1997; White, 2007). Juveniles in MPAs, where predators are generally more abundant and larger, therefore, could undergo higher mortality rates. However, a study about white sea bream in Mediterranean did not detect any significant difference in settlers‟ mortality rates between protected and unprotected areas (Macpherson et al., 1997). From this perspective, in our study, differential 19

ACCEPTED MANUSCRIPT predators abundance could be excluded as an effect of differential mortality (protected vs unprotected areas) in reshaping settlement patterns and in

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explaining the absence of relationship among settler and recruit densities

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recorded. On the other hand a key-role of post-settlement dispersal can be hypothesized due to the high dispersal distance (i.e. up to 30 km) and

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connectivity between protected and unprotected areas detected for studied

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species along the studied area (Di Franco et al. 2012). Although no information is available about dispersal and mortality at phases successive to recruitment (conversely to phase comprise between settlement and recruitment), it could be hypothesized that post recruitment density dependent processes can also

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contribute to shape the patterns of abundance, and particularly the differences in density of adults (among protected and unprotected areas), can also have

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an effect on settlement and success of subsequent life stages. High densities of

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adults in protected areas could lead to high mortality rates of younger specimens and/or to a high dispersal toward unprotected areas due to high

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competition for resources (i.e. through spillover, Abesamis and Russ, 2005). The differences between patterns of settlement and recruitment, and their own variability in space and time detected in the present study, stress the complexity of processes occurring between the arrival of settlers and their subsequent recruitment (Macpherson and Zika, 1999) that can be also related to ontogenetic change in habitat use. Diplodus sargus sargus shows an ontogenetic shift in habitat use with settlers that actively select sheltered habitat between 0 and 2 m (e.g. crannies) and recruits moving deeper and showing a decreased preference for a particular habitat (Machperson, 1998). 20

ACCEPTED MANUSCRIPT As far as the spatial scales are concerned, most studies on fish settlement and recruitment were conducted on small spatial and temporal scales (often single

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scales), while studies conducted on scales of kilometers and across many years

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are quite rare. As several authors have pointed out (e.g. Dayton and Tegner, 1984; Fontes et al., 2011), the scale of a study may influence the patterns

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that emerge. Therefore, future research on early life stages should properly

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assess the related spatial and temporal variability at multiple scales. The present study reveals a high inter-annual variability (although it was not formally tested) in terms of magnitude of settlement and recruitment despite spatial patterns that do not seem to change drastically from year to year. This

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could be attributed to difference in terms of settlement success attributable to a number of environmental factors (i.e. temperature, food availability,

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hydrodynamic patterns) that could be able to affect reproductive potential of

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adults and the successive settlement process. Unfortunately no information regarding this point is currently available for the study area.

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A better understanding of the processes involved in population replenishment in marine coastal systems may help design and set up more and more effective MPAs for fisheries management and conservation needs (Valles et al., 2001). Understanding the importance of the contribution of MPAs to fish population replenishment both within MPAs and in adjacent (fished) areas is critical for improving management of existing MPAs and justify the creation of others.

Acknowledgements

21

ACCEPTED MANUSCRIPT Authors wish to thank C. Vaglio (University of Salento) and Commander U. Adorante (Nucleo Subacqueo Carabinieri, Bari, Italy) and his team (P. Di Pinto,

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G. Simonini, C. Del Console, F. Pichierri, G. Sgariglia, R. Ciccacci, M. Bellini) for

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invaluable assistance during field work. Thanks also to Dr. S. Ciccolella (Director of Torre Guaceto MPA) and his staff for helpful assistance. Many

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thanks are expressed to the associate editor (Dr. Meryl Williams) and to the

Role of the funding sources

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three anonymous reviewers for critically commenting on the manuscript.

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This research was funded by Total Foundation

(http://foundation.total.com/foundation/total-foundation-200090.html) and

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the Italian MIUR (PRIN Project: protocol no. 2008E7KBAE). The funders had no

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role in study design, data collection and analysis, decision to publish, or

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preparation of the manuscript.

References

Abecasis, D., Bentes, L., Erzini, K. 2009. Home range, residency and movements of Diplodus sargus and Diplodus vulgaris in a coastal lagoon: Connectivity between nursery and adult habitats. Estuar. Coast. Shelf S. 85 525–529.

22

ACCEPTED MANUSCRIPT Abesamis, R.A., Russ, G.R., 2005. Desnity-dependent spillover from a marine reserve: long-term evidence. Ecol. Appl. 15, 1798-1812.

T

Adams, A.J., Blewett, D.A., 2004. Spatial patterns of estuarine habitat type

RI P

use and temporal patterns in abundance of juvenile permit, Trachinotus falcatus, in Charlotte harbour, Florida. Gulf and Caribbean Research 16(2),

SC

129–139.

MA NU

Almany, G.R., Berumen, M., Thorrold, S.R., Planes, S., Jones, G.P., 2007. Local replenishment of coral reef fish populations in a marine reserve. Science 316, 742–744.

Anderson, M.J, Gorley, R.N., Clarke, K.R., 2008. PERMANOVA+ for PRIMER:

ED

Guide to software and statistical methods. PRIMER-E: Plymouth, UK. Artegiani, A., Bregant, D., Paschini, E., Pinardi, N., Raicich, F., Russo, A.,

PT

1997. The Adriatic Sea general circulation. Part I: Air-sea interactions and

CE

water mass structure. J. Phys. Oceanogr. 27, 1492- 1514. Beets, J., 1997. Effects of a predatory fish on the recruitment and abundance

AC

of Caribbean coral reef fishes. Mar. Ecol.-Prog. Ser. 148, 11–21. Bohnsack, J.A., Ault, J.A., 1996. Management strategies to conserve marine biodiversity. Oceanography 9(1), 73–82. Botsford, L.W., White, J.W., Coffroth, M.A., Paris, C.B., Planes, S., Shearer, T.L., Thorrold, S.R., Jones, S.R., 2009. Connectivity and resilience of coral reef metapopulations in marine protected areas: matching empirical efforts to predictive needs. Coral Reefs 28, 327–337.

23

ACCEPTED MANUSCRIPT Bussotti, S., Guidetti, P., 2011. Timing and habitat preferences for settlement of juvenile fishes in the Marine Protected Area of Torre Guaceto (south-

T

eastern Italy, Adriatic Sea). Ital. J. Zool. 78, 243-254.

RI P

Caley, M.J., Carr, M.H., Hixon, M.A., Hughes, T.P., Jones, G.P., Menge, B.A.,

Annu. Rev. Ecol. Syst. 27, 477-500.

SC

1996. Recruitment and the local dynamics of open marine populations.

MA NU

Carr, M.H., Syms, C., 2006. Recruitment In The Ecology of Marine Fishes: California and Adjacent Waters (Allen, L. G., Pondella, D. J. & Horn, M., eds), pp.411-427 Berkeley, CA: University of California Press. Cheminee, A., Francour, P., Harmelin-Vivien, M., 2011. Assessment of

ED

Diplodus spp. (Sparidae) nursery grounds along the rocky shore of Marseilles (France, NW Mediterranean). Sci. Mar. 75(1), 181-188.

PT

Connell, S.D., 1997. The relationship between large predatory fish and

CE

recruitment and mortality of juvenile coral reef fish on artificial reefs. J. Exp. Mar. Biol. Ecol. 209, 261-278.

AC

Crechriou, R., Alemany, F., Roussel, E., Chassanite, A., Marinaro, J.Y., Mader, J., Rochel, E., Planes, S., 2010. Fisheries replenishment of early life taxa: potential export of fish eggs and larvae from a temperate marine protected area. Fish. Oceanogr. 19, 135–150. D‟Anna, G., Giacalone, V.M., Pipitone, C., Badalamenti, F., 2011. Movement pattern of white seabream, Diplodus sargus (L., 1758) acoustically tracked in an artificial reef area. Ita. J. Zool. 78(2), 255–263. Dayton, P.K., Tegner, M.J., 1984. The importance of scale in community ecology: a kelp forest with terrestrial analogs. In: Price PW, Slobodchikoff 24

ACCEPTED MANUSCRIPT CN, Gaud WS (eds). A new ecology: novel approaches to interactive systems. Wiley & Sons, New York, pp. 457-481.

T

Di Franco, A., Guidetti, P., 2011. Patterns of variability in early-life traits of

RI P

fishes depend on spatial scale of analysis. Biol. Letters 7, 454–456. Di Franco, A., Bussotti, S., Navone, A., Panzalis, P., Guidetti, P., 2009.

SC

Evaluating effects of total and partial restrictions to fishing on

MA NU

Mediterranean rocky-reef fish assemblages. Mar. Ecol.-Prog. Ser. 387, 275-285.

Di Franco, A., De Benedetto, G., De Rinaldis, G., Raventos, N., Sahyoun, R., Guidetti, P., 2011. Large scale variability in otolith microstructure and

ED

microchemistry: the case study of Diplodus sargus sargus (Pisces: Sparidae) in the Mediterranean Sea. Ita. J. Zool. 78(2), 182–192.

PT

Di Franco, A., Gillanders, B.M., De Benedetto, G., Pennetta, A., De Leo, G.,

CE

Guidetti, P., 2012. Dispersal Patterns of Coastal Fish: Implications for Designing Networks of Marine Protected Areas. PLoS ONE 7(2), e31681.

AC

Doherty, P.J., 1991. Spatial and temperature patterns In recruitment. In: Sale PF (ed.) The ecology of fishes on coral reefs. Academic Press, London, p 261-292. Doherty, P., Fowler, T., 1994. An empirical-test of recruitment limitation in a coral-reef fish. Science 263, 935–939. Evans, R.D., Russ, G.R., Kritzer. J.P., 2008. Batch fecundity of Lutjanus carponotatus (Lutjanidae) and implications of no-take marine reserves on the Great Barrier Reef, Australia. Coral Reefs 27, 179-189.

25

ACCEPTED MANUSCRIPT Fontes, J., Caselle, J.E., Afonso, P., Santos, R.S., 2009. Multi-scale recruitment patterns and effects on local population size of a temperate reef fish. J.

T

Fish Biol. 75, 1271–1286.

RI P

Fontes, J., Afonso, P., Santos, S.R., Caselle, J.E., 2010. Temporal variability of larval growth, size, stage duration and recruitment of a wrasse, Coris julis

SC

(Pisces: Labridae), from the Azores. Sci. Mar. 74(4), 721-729.

MA NU

Fontes, J., Santos, S.R., Afonso, P., Caselle, J.E., 2011. Larval growth, size, stage duration and recruitment success of a temperate reef fish. J. Sea. Res. 65, 1-7.

Forrester, G.E., 1990. Factors Influencing the Juvenile Demography of a Coral

ED

Reef Fish. Ecology 71, 1666-1681.

Grorud-Colvert, K., Sponaugle, S., 2009. Larval supply and juvenile

PT

recruitment of coral reef fishes to marine reserves and non-reserves of

CE

the upper Florida Keys, USA. Mar. Biol. 156, 277–288. Guidetti, P., 2006. Marine reserves reestablish lost predatory interactions and

AC

cause community changes in rocky reefs. Ecol. Appl. 16(3):963-976. Guidetti, P., Sala, E., 2007. Community-wide effects of marine reserves in the Mediterranean Sea. Mar. Ecol.-Prog. Ser. 335, 43–56. Guidetti, P., Milazzo, M., Bussotti, S., Molinari, A., Murenu, M., Pais, A., Spanò, N., Balzano, R., Agardy, T., Boero, F., Carrada, G., Cattaneo-Vietti, R., Cau, A., Chemello, R., Greco, S., Manganaro, A., Notarbartolo di Sciara, G., Russo, G.F., Tunesi, L., 2008. Italian marine reserve effectiveness: Does enforcement matter? Biol. Conserv. 141, 699–709.

26

ACCEPTED MANUSCRIPT Guidetti, P., Bussotti, S., Calò, A., Di Franco, A., Di Lorenzo, M., Qian, K., Mazzoldi, C., Planes, S., Sayhoun, R., Turnone, G., 2011. Reproductive

T

patterns and early life-history traits of the two-banded sea bream

RI P

(Diplodus vulgaris, Geoffroy Saint-Hilaire, 1817) at the Marine Protected Area of Torre Guaceto (SW Adriatic, Italy): implications for management

SC

and conservation. Proceedings of 2011 Congress of Société Zoologique de

MA NU

France, Nice (France).

Harmelin-Vivien, M.L., Harmelin, J.G., Chauvet, C., Duval, C., Galzin, R., Lejeune, P., Barnabe, G., Blanc, F., Chevalier, R., Duclerc, J., Lassere, G., 1985. Evaluation des peuplements et populations de poissons. Méthodes

ED

et problèmes. Rev Ecol Terre Vie 40, 467–539. Harmelin-Vivien, M.L., Harmelin, J.G., Leboulleux, V., 1995. Microhabitat

PT

requirements for settlement of juvenile sparid fishes on Mediterranean

CE

rocky shores. Hydrobiologia 300-301, 309-320. Hasting, A., Botsford, L.W., 2006. Persistence of spatial populations depends

AC

on returning home. Proc. Natl. Acad. Sci. USA 103, 6067–6072. Hixon, M.A., Carr, M.H., 1997. Synergistic predation, density dependence, and population regulation in marine fish. Science 277, 946–949. Hurlbert, S.H., 1984. Pseudoreplication and the design of ecological field experiments. Ecological Monographs 54(2), 187–211. Kingsford, M.J., 1988. The early life history of fish in coastal waters of New Zealand: a review. New Zeal. J. Mar. Fresh. 22, 463-480.

27

ACCEPTED MANUSCRIPT Legget, W.C., Deblois, E., 1994. Recruitment in marine fishes: is it regulated by starvation and predation in the egg and larval stages? Neth. J. Sea Res

T

32, 119-134.

RI P

Leis, J. M., Siebeck, U., Dixson, D.L., 2011. How Nemo Finds Home: The Neuroecology of Dispersal and of Population Connectivity in Larvae of

SC

Marine Fishes. Integr. Comp. Biol. 5, 826-843.

MA NU

Levin, P.S., 1994. Fine-scale temporal variation In recruitment of a temperate demersal flsh: the importance of settlement versus post-settlement loss. Oecologia 97, 124-133.

Lino, P.G., Bentes, L., Abecasis, D., Neves dos Santos, M., Erzini, K., 2009.

ED

Comparative Behavior of wild and hatchery reared white sea bream (Diplodus sargus) released on artificial reefs off the algarve (Southern

PT

Portugal). J.L.L. Nielsen et al. (eds), Tagging and Tracking of Marine

CE

Animals with Eletronic Devices, Reviews: Methods and Technologies in Fish Biology and Fisheries 9, Springer Science+Business Media B.V. 2009.

AC

Lloret, J., Zaragoza, N., Caballero, D., Riera, V., 2008. Biological and socioeconomic implications of recreational boat fishing for the management of fishery resources in the marine reserve of Cap de Creus (NW Mediterranean). Fish. Res. 91, 252–259. Macpherson, E., 1998. Ontogenetic shifts in habitat use and aggregation in juvenile sparid fishes. J. Exp. Mar. Biol. Ecol. 220, 127-150. Macpherson, E., Zika, U., 1999. Temporal and spatial variability of settlement success and recruitment level in three blennoid fishes in the northwestern Mediterranean. Mar. Ecol.-Prog. Ser. 182, 261-282. 28

ACCEPTED MANUSCRIPT Macpherson, E., Biagi, F., Francour, P., Garcia-Rubies, A., Harmelin, J., Harmelin-Vivien, M., Jouvenel, J.Y., Planes, S., Vigliola, L., Tunesi, L.,

T

1997. Mortality of juvenile fishes of the genus Diplodus in protected and

RI P

unprotected areas in the western Mediterranean Sea. Mar. Ecol.-Prog. Ser 160,135–147.

SC

Mapstone, B.D., Fowler, A.J., 1988. Recruitment and the structure of

MA NU

assemblages of fish on coral reefs. Trends Ecol Evol 3, 72-77. Mouine, N., Francour, P., Ktari, M., Chakroun-Marzouk, N., 2007. The reproductive biology of Diplodus sargus sargus in the Gulf of Tunis (central Mediterranean). Sci. Mar. 71(3), 461-469.

ED

Oddo, P., Pinardi, N., Zavatarelli, M., 2005. A numerical study of the interannual variability of the Adriatic Sea (1999–2002). Sci. Total Environ.

PT

353, 39–56, 2005.

CE

Pelc, R.A., Warner, R.R., Gaines, S., Paris, C.B., 2010. Detecting larval export from marine reserves. PNAS 107(43), 18266–18271.

AC

Raventos, N., 2009. Relationships between adult population size, recruitment, and year-class strength in a labrid fish in the Mediterranean Sea. Estuar. Coast. Shelf S. 85, 167–172. Roberts, C.R.,. Polunin, N.V.C., 1991. Are marine reserves effective in management of reef fisheries? Reviews of Fish Biology and Fisheries 1, 65–91. Sano, M., 1997. Temporal variation in density dependence: Recruitment and postrecruitment demography of a temperate zone sand goby. J. Exp. Mar. Biol. Ecol. 214, 67-84. 29

ACCEPTED MANUSCRIPT Schmitt, R.J., Holbrook, S.J., 1999. Settlement and recruitment of three damselfish species: larval delivery and competition for shelter space.

T

Oecologia 118, 76–86.

RI P

Schmitt, R.J., Holbrook, S.J., 2002. Spatial Variation in Concurrent Settlement of Three Damselfishes: Relationships with Near-Field Current Flow.

SC

Oecologia 131, 391-401.

MA NU

Sponaugle, S., Fortuna, J., Grorud, K., Lee, T., 2003. Dynamics of larval fish assemblages over a shallow coral reef in the Florida Keys. Mar. Biol. 143, 175–189.

Swearer, S.E., Caselle, J.E., Lea, D. W., Warner, R.R., 1999. Larval retention

ED

and recruitment in an island population of a coral-reef fish. Nature 402, 799–802.

PT

Tortonese, E., 1965. Biologie comparée de trois espèces méditerranéennes de

CE

Diplodus (Pisces, Sparidae). Rapp. Commission International pour l‟Exploration Scientifique de la Mer Méditérranée 18, 189-192.

AC

Underwood, A.J., 1997. Experiments in Ecology : Their Logical Design and Interpretation Using Analysis of Variance. Cambridge University Press. 504 pp. White, J. W., 2007. Spatially correlated recruitment of a marine predator and its prey shapes the large-scale pattern of density-dependent prey mortality. Ecology Letters 10, 1054-1065. Valles, H., Sponaugle, S., Oxenford, H.A., 2001. Larval supply to a marine reserve and adjacent fished area in the Soufriere Marine Management Area, St Lucia, West Indies. J. Fish Biol. 59, 152–177. 30

ACCEPTED MANUSCRIPT Victor, B.C., 1986. Larval settlement and juvenile mortality in a recruitmentlimited coral reef population. Ecol. Monogr. 56, 145-160.

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Vigliola, L., 1998. Contrôle et régulation du recruitment des sparidae

RI P

(Poissons, Téléostéens) en Méditerranée: importance des processus préet post-installation benthique. PhD thesis, University Aix-Marseille II.

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Vigliola, L., Harmelin-Vivien, M.L., Biagi, F., Galzin, R., Garcia-Rubies, A.,

MA NU

Harmelin, J.G., Jouvenel, J.Y., Le Direach-Boursier, L., Macpherson, E., Tunesi, L., 1998. Spatial and temporal patterns of settlement among sparid fishes of the genus Diplodus in the northwestern Mediterranean.

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PT

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Mar. Ecol. Prog. Ser. 168, 45–56.

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ACCEPTED MANUSCRIPT Tab. 1. PERMANOVA on density of 1-YOs in 2010 and 2011 and adults in 2010. ns: not significant; *p < 0.05, **p < 0.01; ***p < 0.001. For factor labels see Materials and Methods. Adults

Source

d.f.

MS

Pseudo- f

MS

Pseudo- f

GD

2

50.79

3.04 ns

29.51

4.09 *

Si(GD)

11

16.69

2.37 *

7.21

Res

98

7.01

Total

111

1.94 *

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3.70

32

2010

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2011

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2010

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1-YOs

MS

Pseudo- f

23.84

5.80 *

4.10

2.39 *

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Methods.

2009 d.f.

MS

Pseudo- f

GD

2

374.16

Si(GD)

11

Res

210

Total

223

MS

2009

Pseudo- f

d.f. MS

2010

Pseudo- f

MS

Pseudo- f

29.08.01 3.47 *

2

0.65

0.05 ns

4.93

1.96 ns

64.06 3.86 ***

8.37

4.59 ***

11

12.88

12.79 ***

2.51

2.49 **

16.55

1.82

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5.84 *

2010

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Recruits

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Settlers

98

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111

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1.01

1.01

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Figure 1. Study area. Arrows indicate the sampling sites. Black arrows indicate sites within TGMPA, dark grey arrows indicate sites northern TGMPA borders and light

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grey arrows indicate sites southern TGMPA borders. Dotted black arrow indicates

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main current direction in the study area during the period of spawning and

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settlement of the white sea bream.

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Figure 2. Density (mean ± SE) of a) settlers, b) recruits, c) 1-YOs and d) adults per transect in each sampling site. Two sampling years, when available, are shown separately.

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Fig 3. Size frequency distributions of adults white sea bream in the three different

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geographic directions.

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Figure 4. Mean values per site of a) recruit density vs settler density in two sampling years, b) 1-YO density vs recruit density in two sampling years (2009 recruits

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sampling/2010 1YO sampling; 2010 recruits sampling/2011 1YO sampling), c) adult (>18 cm) density vs recruit density. Bars indicate standard errors.

Figure 5. Mean values per site of settler density vs PLD (pelagic larval duration). Bars indicate standard errors. Note that PLD scale starts from 13 days.

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ACCEPTED MANUSCRIPT Research Highlights

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 We assessed fish density at multiple life stages within an MPA and in

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nearby unprotected areas

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 Density of settlers did not differ in relation to the protection level  Density of recruits only revealed variability among sites, but not between

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protection levels

 No significant relationships were found among different life stages at the site scale

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 Results suggest a decoupling in space between the sequential life history

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stages

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