Where did this refuse come from? Marine anthropogenic litter on a remote island of the Colombian Caribbean sea

Marine Pollution Bulletin 149 (2019) 110611

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Baseline

Where did this refuse come from? Marine anthropogenic litter on a remote island of the Colombian Caribbean sea

T

Nelson Rangel-Buitragoa,b,∗, Adriana Gracia C.b, Anubis Velez-Mendozab, Alexander Carvajal-Floriánb, Lilibeth Mojica-Martinezb, William J. Nealc a

Programa de Física, Facultad de Ciencias Básicas, Universidad del Atlántico, Barranquilla, Atlántico, Colombia Programa de Biología, Facultad de Ciencias Básicas, Universidad del Atlántico, Barranquilla, Atlántico, Colombia c Department of Geology, Grand Valley State University, The Seymour K. & Esther R. Padnos Hall of Science 213A, Allendale, MI, USA b

ARTICLE INFO

ABSTRACT

Keywords: Islands Marine anthropogenic litter Cleanliness Hazardous items Colombia

On the Colombian continental shelf, 12 km SW of the municipality of Galerazamba, Department of Bolívar, is the northern-most island of the Colombian Caribbean: Isla Arena. Despite being remote and uninhabited, this island is being affected by one of the most persistent problems in the marine environment: Marine Anthropogenic Litter (MAL). In this first Colombian insular MAL study, a total of 1436 MAL items were collected along Isla Arena, equivalent to an average abundance of 2.87 items/m2. MAL items belong to 54 categories that are grouped in nine material typologies. These typologies include plastic (36 categories), metal (6), glass (3), medical waste (3), machined wood (2), pottery (1), sanitary waste (1), rubber (1) and cloth (1). Isla Arena now is considered as an “Extremely dirty” site in terms of the Clean Coast Index. Hazardous litter items (sharp and toxic) occur in percentages as high as 10.2% (146 items, Avg: 0.29 items/m2). Along the island, current MAL amounts are so elevated that simple clean-up operations are an insufficient solution, and restoration measures are needed. MAL mainly comes from land-based sources, primarily generated by activities in the adjacent mainland river basins and coastal urban developments, particularly in the area of beaches. Marine anthropogenic litter found on Isla Arena reflects a strong influence from longshore-current transport. Management solutions need to begin at the same litter sources, and must include analytics, policy reforms and enforcement, and private and public investments.

Implicit in working definitions of islands (Masselink and Hughes, 2003; Davis and Fitzgerald, 2004; Davidson-Arnott, 2010) is that they are accessible, even if remote and accessible only by boat and then afoot (Ratter, 2018). Islands are incredibly dynamic environments, generated on high and low-lying coastal margins, occurring in all latitudes, and serving as habitat for a vast range of organisms (Menard, 1986; Royle, 2014; Kueffer and Keaohanuiopuna, 2017). Islands, especially the tropical and subtropical, are hotspots of biodiversity, hosting diverse ecosystems such as seagrass beds, mangroves and coral reefs (Nurse et al., 2001; Sciolo et al., 2016). The characteristics of size, shape, and degree of isolation make island environments ecologically unique. At the same time, islands are one of the most vulnerable environments on Earth and a diversity of processes severely threaten them. These processes include climate change (Campbell and Barnett, 2010), sea level rise (Leatherman and Beller-Simms, 1997; Williams et al., 2018), unsustainable use of local resources (UNEP, 2009),

∗

overpopulation (Rangel-Buitrago et al., 2018), and litter (Bergmann and Gutow, 2015; Lavers and Bond, 2017; Lavers et al., 2019; Williams and Rangel-Buitrago, 2019). The fragility of these environments is so evident, that according to IUCN (2019), eighty percent of known species extinctions have occurred on islands, and currently, about 45 percent of Red List endangered species are related to these environments. Litter can be defined as all human-created material that has been discharged into the environment. Specifically, Marine Anthropogenic Litter (MAL) includes all anthropogenic, manufactured, or processed solid materials (regardless of size) discarded, disposed of, or abandoned in the marine environment, including all materials discarded into the sea, or brought indirectly to the sea by rivers, sewage discharge, waves, tides, currents and winds (Derraik, 2002; Gall and Thompson, 2015; Stachowitsch, 2019; Williams and Rangel-Buitrago, 2019). Marine anthropogenic litter influences encompass the entire marine environment, impacting all of this setting negatively (Angiolillo, 2019).

Corresponding author. Programa de Física, Facultad de Ciencias Básicas, Universidad del Atlántico, Barranquilla, Atlántico, Colombia. E-mail address: [email protected] (N. Rangel-Buitrago).

https://doi.org/10.1016/j.marpolbul.2019.110611 Received 10 July 2019; Received in revised form 6 September 2019; Accepted 18 September 2019 Available online 17 October 2019 0025-326X/ © 2019 Elsevier Ltd. All rights reserved.

Marine Pollution Bulletin 149 (2019) 110611

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Its generation has been identified as one of the problems in need of an urgent solution (Pilkey et al., 2011; Pilkey and Cooper, 2014). The scale of the problem is such that MAL can be considered as a problem without borders with immeasurable and irreversible environmental costs. Marine anthropogenic litter presence is so omnipresent in the marine environment that its distribution and high magnitudes have been suggested as one of the indicators of the Anthropocene epoch (Ellis et al., 2011; Price et al., 2011; Zalasiewicz et al., 2016). In essence, the MAL is one of the most significant challenges that humankind is currently facing. Islands are not immune to MAL. In fact, due to their geomorphologic characteristics, islands may become sink areas where MAL accumulate in high quantities (Lebreton et al., 2018; Ríos et al., 2018). Marine anthropogenic litter on islands is related to diverse factors such as sources and oceanographic conditions. However, hydrodynamic conditions, specifically surface currents, play the leading role in the transport and accumulation of MAL in these environments (Maximenko et al., 2012). According to Hidalgo-Ruz and Thiel (2013), Pieper et al. (2015), Andrades et al. (2018) and Ríos et al. (2018), exposure to winds and current flows is mainly responsible for the significant amounts of MAL recorded along islands of the Atlantic and Pacific Ocean such as the Azores, Trindade (Brazil), Henderson (Pitcairn Islands), and Rapa Nui (Easter Island). Several studies exist regarding magnitudes, composition, distribution, and sources of MAL along the Caribbean continental coastline of Colombia (Gracia et al., 2018; Rangel-Buitrago et al., 2017, 2018 and 2019a and b; Williams et al., 2016a). However, MAL magnitudes and impacts on insular areas of Colombia is still a topic to explore, especially if one considers that Colombia counts 55 islands; eleven located on the Pacific Coast and forty-four located in the Caribbean Sea. This baseline paper presents for the first time the magnitudes and impacts of MAL present on Colombia's insular territories. The target area is Isla Arena, a remote and uninhabited island located in the central part of the Colombian Caribbean. In this work the Clean Coast Index (CCI) and the Hazardous Items Index (HII) were used to measure the current environmental status of this island. The analysis of these indices as indicators of marine pollution provides opportunities to try to understand, and solve this problem; generated far from the islands, but severely impacting these unique territories of Colombia. Isla Arena belongs to Bolivar Department and is located on the central part of the Caribbean Sea of Colombia (Fig. 1) with approximate co-ordinates of 10° 44´ 20.83" N lat. and 75° 21´ 03.35" W long. (not to be mistaken for Isla Arenas farther to the southwest). This uninhabited island has an area of 4122 m2 and a perimeter of 378 m. Elevations are less than 1.3 m which makes the narrow island subject to overwash, and deposition of litter into the island's interior. This island is the barely emergent part of a dormant carbonate bank (Fig. 2) that owes its emergence to mud diapirism; a typical process of the central Caribbean coast of Colombia (Bosence, 2005; Gracia et al., 2012). The platform's origin is related to the rise of a series of mud volcanoes relative to a base level that has resulted in a seafloor high. When these seafloor highs extend into the zone of significant carbonate production, they develop limestone platforms which in turn give shape to the island. Currently, the study area is a shallow-marine site, isolated from any direct siliciclastic supply, and is a suitable substrate for carbonate growth, made up mostly of corals, seagrasses, and algae. According to Pinzón et al. (1998), a total of 33 species compose the benthic community of the island. Of these, 14 species are stony corals, 5 are zoanthids, 1 is an octocoral, 1 is an anemone, 10 are macroalgae, and 2 are seagrasses. These same authors identified ten ecological zones, each of them dominated by at least one species. Isla Arena is located in a semi-arid tropical environment with an average temperature of 30 °C and precipitation values up to 2700 mm/ yr (Rangel-Buitrago et al., 2013). The rainfall regime in the island presents two dry periods (December–March and July–September) and two rainy periods (April–May and October–November) while wind

velocity has values lower than 15 m/s (Rangel-Buitrago et al., 2018). On this Island as well as, this part of the Caribbean of Colombia, tides have maximum amplitudes of 70 cm and are typical of a mixed semi-diurnal, micro-tidal environment (Rangel-Buitrago et al., 2017, 2018). According to Gracia et al. (2018), the average significant wave height in this area of the Caribbean of Colombia is 1.7 m and the peak period average is 7.3 s. From November to July, wave systems along the island are dominated by NE swells while for the remainder of the time waves from NW, WSW, and even SW occur. Longshore currents have a dominant SW component, but a minor reversal to the NW occurs during the two rainy periods (Anfuso et al., 2015). For MAL analysis, Isla Arena was divided into two sectors (windward and leeward), each one with and area of 250 m2 (50 m length and 5 m wide, Fig. 2). Within each of these sectors, all MAL available was collected and then separated according to one of the 135 typologies presented on the OSPAR classification (OSPAR, 2010, Figs. 3 and 4; Table 1). Collected items were separated and counted to measure and compare the amount of MAL available in each of the sectors, and also in the whole island. In order to compare data obtained along Isla Arena with those obtained in other world sites, MAL results were presented as item quantities and associated densities per square meter (items/m2). Marine anthropogenic litter categories can be grouped and used for the determination of the economic sector or human activity from which it originates (source). In this work, all MAL typologies found were grouped using the classification proposed by the Ocean Conservancy in 2010. This classification relates MAL items with the most probable economic sector or human activity, which can be responsible for its origin (source). Marine anthropogenic litter environmental impacts along the island were assessed by means two environmental indexes: the Clean Coast Index (CCI) and the Hazardous Items Index (HII). The CCI determines the state of being free from MAL (cleanliness), and the habit of achieving and maintaining that state (Rangel-Buitrago et al., 2019a). In order to evaluate the cleanliness of each sector and the whole island, the CCI was calculated using the formula:

CCI =

TotalMDItems Area

K

The CCI allows assessing island cleanliness in five different classes that range from “very clean” to “extremely dirty” according to the scale provided by Alkalay et al. (2007). The second index used was the Hazardous Items Index (HII) developed by Rangel-Buitrago et al. (2019c). This index measures the possibility of being affected by hazardous (sharp and toxic) items in a coastal area. The HII of each sector and the whole Island was calculated using the formula:

HII =

HazardousMDitems log10 TotalMDItems

Area

K

Where HII is the number of hazardous items per square meter, taking into account the existing relationship between hazardous items and the log10 of the total number of all items found per surveyed area (RangelBuitrago et al., 2019c). The HHI allows assessing the beach environmental quality in terms of hazardous items in five different classes that range from I “Safe site - no hazardous items” to V “Extremely hazardous site - too many hazardous items.” According to Rangel-Buitrago et al. (2019c), the HII index can be estimated taking into account the total amount of hazardous items or distinguishing between toxic items (medical and sanitary waste) and sharp items (metal, glass, and pottery). The Clean Coast Index and the Hazardous Items Index were integrated through a sector analysis using the methodology presented by Williams et al. (2016a,b). Here, a table was constructed using the percentile technique (Langford, 2006), and this table was divided into 2

Marine Pollution Bulletin 149 (2019) 110611

N. Rangel-Buitrago, et al.

Fig. 1. Location and general characteristics of Isla Arena.

• The red area describes dirty to extremely dirty areas with a high

amount of hazardous items where urgent intervention and even restoration measures are necessary.

Lastly to define MAL-transport patterns, data obtained from the reanalysis of wind data available from the North American Regional Reanalysis database (NARR) were used. In this case, three typical scenarios were modeled using average and extreme waves from the main approach directions (NE, NW, and SW). This analysis was developed by means the Coastal Modelling System (SMC) program, developed by the Hydraulics Institute of the University of Cantabria (Spain). This software produces realistic estimates of random, short-crested wind-generated waves in different conditions for a given bottom bathymetry, wind field, water level, and currents field. Isla Arena is a clear example of a remote island according to the Bathing Area Registration and Evaluation Systems (BARE) presented by Williams and Micallef (2009). This island is only accessible by boat, and due its size it is uninhabited. Marine anthropogenic litter collected belongs to 54 categories that can be grouped into nine material typologies (Table 1). These include plastic (36 categories), metal (6), glass (3), medical waste (3), machined wood (2), pottery (1), sanitary waste (1), rubber (1) and cloth (1). Along the entire island, MAL was observed, and a total of 1436 items were recovered from the 500 m2 surveyed (Table 1 and Figs. 3 and 4). Overall MAL distribution ranged from 521 items on the leeward area to 915 items on the windward side. MAL average was 2.87 items/ m2, but these values varied substantially between sites. Highest abundance regarding MAL density was observed in the windward area (3.66 items/m2) while the leeward had a density of 2.08 items/m2 (Table 1). Marine anthropogenic litter densities found along Isla Arena were similar to the values determined by Al-Najjar and Al-Shiyab (2011) on the Gulf of Aqaba (2.5 items/m2), Ríos et al. (2018) on the Azores archipelago (3–4 items/m2), Andrades et al. (2018) on Trindade Island, Brazil (2.5 items/m2) and Lavers et al. (2019) on Gun beach on the Keeling Islands, Australia (3.6 items/m2). Plastic items were the most common MAL typology found along Isla

Fig. 2. a) The submerged platform on which the emergent Isla Arena formed at eastern end. b) View west with the two study sampling areas outlined in red (windward to right, leeward to left). (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)

three areas (Fig. 5).

• The green area which shows very clean and clean areas without •

hazardous items where protection measures are necessary to maintain current conditions. The orange area represents moderate cleanliness sites with a considerable amount of hazardous items and where cleaning actions are necessary. 3

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Fig. 3. Examples of Marine anthropogenic litter collected on Isla Arena. This MAL belongs to 54 categories that can be grouped on nine material typologies, these include plastic (36 categories), metal (6), glass (3), medical waste (3), wood machined (2), pottery (1), sanitary waste (1), rubber (1) and cloth (1). Note the dominance of plastics. The natural sand and gravel is skeletal carbonate material (note especially lower left photo).

Fig. 4. Marine anthropogenic litter percentages along Isla Arena.

Arena with 1272 items (2.5 item/m2) corresponding with 88.6% of total (Fig. 4). Specifically, 465 plastic items (1.86 items/m2) were found in the leeward area, while 807 plastic items (3.23 items/m2) were found in the windward. In the same way, eight of the top ten items

found (77.43% of total) were all plastic items, confirming that plastic is extremely abundant in the Caribbean coast of Colombia (Williams et al., 2016a, Gracia et al., 2018 and Rangel-Buitrago et al., 2018 and 2019a) as well as other islands of the world (Corbin and Singh., 1993; Agustin 4

Marine Pollution Bulletin 149 (2019) 110611

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Table 1 Categories, types, sources, numerical amounts, densities (items/m2) and percentages of marine anthropogenic litter observed along Isla Arena. OSPAR CODE

ITEM

2 112 4

Bags (e.g. shopping) Plastic bag ends Drinks (bottles, containers and drums)

Plastic Plastic Plastic

5 7

Plastic Plastic

11 12

Cleaner (bottles, containers and drums) Cosmetics (bottles & containers e.g. sun lotion, shampoo, shower gel, deodorant) Engine oil containers and drums < 50 cm Jerry cans (square plastic containers with handle) Injection gun containers Other bottles, containers and drums

13 14 15

Crates Car parts Caps/lids

Plastic Plastic Plastic

16 17 18 19

Cigarette lighters Pens Combs/hair brushes Crisp/sweet packets and lolly sticks

Plastic Plastic Plastic Plastic

20 21

Toys & party poppers Cups

Plastic Plastic

22

Cutlery/trays/straws

Plastic

23 31 32 115 116 33 37 38 39 40 41 44

Fertiliser/animal feed bags Rope (diameter more than 1 cm) String and cord (diameter less than 1 cm) Nets and pieces of net < 50 cm Nets and pieces of net > 50 cm Tangled nets/cord/rope and string Floats/Buoys Buckets Strapping bands Industrial packaging, plastic sheeting Fibre glass Shoes/sandals

Plastic Plastic Plastic Plastic Plastic Plastic Plastic Plastic Plastic Plastic Plastic Plastic

45 117 46

Plastic Plastic Plastic

47 48 52 54 74

Foam sponge Plastic/polystyrene pieces 0–2,5 cm Plastic/polystyrene pieces 2,5 cm > < 50 cm Plastic/polystyrene pieces > 50 cm Other plastic/polystyrene items Tyres and belts Clothing Other wood < 50 cm

75

Other wood > 50 cm

76 77

Aerosol/Spray cans Bottle caps

Plastic Plastic Rubber Cloth Wood (machined) Wood (machined) Metal Metal

78

Drink cans

Metal

81 83 89 91 92 93 94 102

Foil wrappers Industrial scrap Other metal pieces < 50 cm Bottles Light bulbs/tubes Other glass items Construction material e.g. tiles Other sanitary items

Metal Metal Metal Glass Glass Glass Pottery Sanitary Waste

103

Containers/tubes

Medical Waste

104

Syringes

Medical Waste

8 10

TYPE

Plastic Plastic Plastic Plastic

SOURCE

LEEWARD

WINDWARD

TOTAL

N°

Density

%

N°

Density

%

N°

Density

%

Dumping Dumping Shoreline and Recreational Dumping Medical and Sanitary Waste Ocean/waterway Ocean/waterway

1 0 163

0.004 0 0.652

0.19 0.00 31.29

6 1 238

0.024 0.004 0.952

0.66 0.11 26.01

7 1 401

0.014 0.002 0.802

0.49 0.07 27.92

25 8

0.1 0.032

4.80 1.54

10 18

0.04 0.072

1.09 1.97

35 26

0.07 0.052

2.44 1.81

15 0

0.06 0

2.88 0.00

33 1

0.132 0.004

3.61 0.11

48 1

0.096 0.002

3.34 0.07

Dumping Medical and Sanitary Waste Dumping Dumping Shoreline and Recreational Smoking-Related Dumping Dumping Shoreline and Recreational Dumping Shoreline and Recreational Shoreline and Recreational Dumping Ocean/waterway Ocean/waterway Ocean/waterway Ocean/waterway Ocean/waterway Ocean/waterway Ocean/waterway Ocean/waterway Dumping Ocean/waterway Shoreline and Recreational Ocean/waterway Dumping Dumping

2 6

0.008 0.024

0.38 1.15

0 16

0 0.064

0.00 1.75

2 22

0.004 0.044

0.14 1.53

0 3 125

0 0.012 0.5

0.00 0.58 23.99

1 1 244

0.004 0.004 0.976

0.11 0.11 26.67

1 4 369

0.002 0.008 0.738

0.07 0.28 25.70

0 0 0 1

0 0 0 0.004

0.00 0.00 0.00 0.19

7 1 3 1

0.028 0.004 0.012 0.004

0.77 0.11 0.33 0.11

7 1 3 2

0.014 0.002 0.006 0.004

0.49 0.07 0.21 0.14

0 0

0 0

0.00 0.00

10 8

0.04 0.032

1.09 0.87

10 8

0.02 0.016

0.70 0.56

3

0.012

0.58

4

0.016

0.44

7

0.014

0.49

0 1 1 0 0 0 0 0 1 0 3 16

0 0.004 0.004 0 0 0 0 0 0.004 0 0.012 0.064

0.00 0.19 0.19 0.00 0.00 0.00 0.00 0.00 0.19 0.00 0.58 3.07

1 1 4 1 3 3 1 1 2 4 6 35

0.004 0.004 0.016 0.004 0.012 0.012 0.004 0.004 0.008 0.016 0.024 0.14

0.11 0.11 0.44 0.11 0.33 0.33 0.11 0.11 0.22 0.44 0.66 3.83

1 2 5 1 3 3 1 1 3 4 9 51

0.002 0.004 0.01 0.002 0.006 0.006 0.002 0.002 0.006 0.008 0.018 0.102

0.07 0.14 0.35 0.07 0.21 0.21 0.07 0.07 0.21 0.28 0.63 3.55

24 1 5

0.096 0.004 0.02

4.61 0.19 0.96

28 3 57

0.112 0.012 0.228

3.06 0.33 6.23

52 4 62

0.104 0.008 0.124

3.62 0.28 4.32

Dumping Dumping Dumping Dumping Dumping

10 51 1 1 2

0.04 0.204 0.004 0.004 0.008

1.92 9.79 0.19 0.19 0.38

11 43 1 1 5

0.044 0.172 0.004 0.004 0.02

1.20 4.70 0.11 0.11 0.55

21 94 2 2 7

0.042 0.188 0.004 0.004 0.014

1.46 6.55 0.14 0.14 0.49

Dumping

3

0.012

0.58

4

0.016

0.44

7

0.014

0.49

Dumping Shoreline and Recreational Shoreline and Recreational Dumping Dumping Dumping Dumping Dumping Dumping Dumping Medical and Sanitary Waste Medical and Sanitary Waste Medical and Sanitary Waste

4 5

0.016 0.02

0.77 0.96

3 15

0.012 0.06

0.33 1.64

7 20

0.014 0.04

0.49 1.39

1

0.004

0.19

2

0.008

0.22

3

0.006

0.21

1 1 0 15 0 9 1 2

0.004 0.004 0 0.06 0 0.036 0.004 0.008

0.19 0.19 0.00 2.88 0.00 1.73 0.19 0.38

3 5 2 23 2 12 4 2

0.012 0.02 0.008 0.092 0.008 0.048 0.016 0.008

0.33 0.55 0.22 2.51 0.22 1.31 0.44 0.22

4 6 2 38 2 21 5 4

0.008 0.012 0.004 0.076 0.004 0.042 0.01 0.008

0.28 0.42 0.14 2.65 0.14 1.46 0.35 0.28

9

0.036

1.73

19

0.076

2.08

28

0.056

1.95

0

0

0.00

3

0.012

0.33

3

0.006

0.21

(continued on next page)

5

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Table 1 (continued) OSPAR CODE

ITEM

TYPE

105

Other medical items (swabs, bandaging etc.)

Medical Waste

SOURCE

LEEWARD

Medical and Sanitary Waste

Total

WINDWARD

TOTAL

N°

Density

%

N°

Density

%

N°

Density

%

1

0.004

0.19

2

0.008

0.22

3

0.006

0.21

521

2.084

100

915

3.66

100

1436

2.872

100

litter issue are taken into account. Clearly the imperative necessity of an in-depth analysis of this specific group of hazards has been underestimated for many years: Hazardous Marine Anthropogenic Litter (HMAL). According to Rangel-Buitrago et al. (2019b), HMAL is all discarded items that can generate a potential danger (direct or indirect) to any living creature. These same authors divide HMAL according to its characteristics and related impacts into two specific types:

• Sharp items: which having an edge or point that can cut or pierce (i.e., metal, glass, and pottery). • Toxic items: which refer to all items which can cause direct and indirect physiological damages (i.e., drug paraphernalia, medical and sanitary waste).

Fig. 5. Sector Analysis Approach. Integration of Clean Coast Index (CCI) with Hazardous Items Index (HHI). This approach confirms that Isla Arena presents considerable MAL magnitudes which currently are negatively influencing cleanliness (CCI) and safety in terms of toxic and sharp MD items presence (HHI).

Along Isla Arena, the percentage of HMAL reached a high of 10.2% (146 items of 1436 total items collected). Hazardous MAL averages 0.29 items/m2, but this value changed between island sides. Highest abundance/density was observed on the windward side (0.38 items/ m2), while the leeward area had a density of 0.19 items/m2. The general Hazardous Item Index (HII) for the entire island was 1.8, which categorized it as a Class III site, indicating that a lot of hazardous items are on the beach face of the island. This same analysis highlights that both sides of the island are in class III. Sharp items dominated the totality of HMAL (108 items). Specifically, 61 pieces of glass, 42 metal pieces, and five items of pottery were found, all of them equivalent to an average abundance of 0.21 items/m2. The highest abundance was observed on the windward side (0.28 items/m2) while the leeward area had a density of 0.14 items/m2. Concerning toxic items, 38 items (0.07 items/m2) were found in the study area (Medical Waste: 34 items, Sanitary Waste: 4 items). The sharp and toxic Hazardous Index (HII) was 1.4 (class III) and 0.5 (class II) respectively, with the windward side being most polluted by hazardous items. Rangel-Buitrago et al. (2019b) calculated the Environmental Status Index (ESI - Schulz et al., 2013) for a mainland area close to the island (25 beaches belonging to the Atlantico Department located only 7 km NE of the island). The ESI is as an indicator that translates the quality of any coastal site in terms of indirect and direct damages to the health of coastal organisms with a scale ranging from 1 to 4 (where 1 = Good,

et al., 2015; Sciolo et al., 2016; Lavers and Bond, 2019). These elevated abundances are mainly related to three factors: i) constant inputs from inland areas (Topçu et al., 2013; Williams and Rangel-Buitrago, 2019), ii) item's resistance and durability (Derraik, 2002; Hardesty et al., 2016) and iii) high buoyancy (Rech et al., 2014, 2018). Other MAL groups found were glass 4.2% (0.122 items/m2), metal 2.9% (0.084 items/m2), medical waste 2.4% (0.068 items/m2), and machined wood 1% (0.028 items/m2). Pottery, sanitary waste, rubber, and cloth groups represent less than 1% with an average density of 0.026 items/m2 (Fig. 4). The Clean Coast Index analysis developed in each of the island sectors shows both sides as extremely dirty with values of 41.68 for the leeward area and 73.2 for the windward one respectively. Taking into account the whole surveyed area (500 m2), Isla Arena reaches a CCI overall value of 57.44, which gives a rank of extremely dirty. Collateral effects of the MAL include injuries to beach users, and despite the importance, scientific research about the topic is still very limited, demanding significant efforts to understand and prevent this hazard. Authors such as Philipp et al. (1991), Ivar do Sul and Costa (2007), Novotny et al. (2009) and Campbell et al. (2019) highlight that understanding how MAL affects human and ecosystem health is a topic in need of exploration, especially if the magnitude and extension of the

Table 2 Environmental Status Index (ESI - Schulz et al., 2013) applied along the Atlantico Department by Rangel-Buitrago et al. (2019a). The ESI is as an indicator that translates the quality of any coastal site in terms of indirect and direct damages to the health of coastal organisms. Due to its proximity and similarities between litter typologies, the ES classification table can be applied using the data collected along Isla Arena. MAL Category

Plastic Rubber Cloth Processed Wood Metal Glass Biohazards

Classification (xi – number of items) developed for the Atlantico Department beaches

Weight

Good

Mediocre

Unsatisfactory

Bad

Wi

less 63 less 5 0 0–1 0–1 0–1 0

64–141 6–15 1–2 2–4 2–3 2–3 1–2

142–285 16–25 2–3 5-9t 4–6 4–6 3–4

more 285 more 25 more 4 more 10 more 6 more 7 more 5

1.5 1.5 1.5 1.5 1 1 1

6

Isla Arena

1272 2 2 14 42 61 38

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Beaches located close to the island are characterized by medium to high levels of anthropogenic activities (mainly tourism). Along these beaches elevated abundances of MAL items are found that are directly generated by beachgoers (in some beaches MAL can reach densities of 8 items/ m2). In this regard, the behavior is always the same: MAL items such as bottles, caps, shoes, are discarded at the same beach after activities such as eating, drinking and picnicking, and then they are moved to remote sites, such as Isla Arena, as a result of interaction with hydrodynamic processes. In the same way, MAL management on these beaches is a complex issue because basic disposal facilities along most of the area do not exist. Due to its geographical position, Isla Arena is highly influenced by three mainland drainage basins that discharge along the Atlantico and Bolivar Department's coastlines. The most important of these is the Magdalena River basin, which is the most significant river system in all Colombia, with a basin that covers 258.430 km2, occupying the 65% of the country's total area. This basin encompasses 724 municipalities, concentrating 80% of the total population of all country. The other two influencing basins are denominated as the “Caribe” and “Mallorquin” basins which drain an area of 1360 km2. Both coastal basins encompass 12 municipalities of both departments concentrating 30 small rivers that flow directly to the sea, and where at least 1,800,600 inhabitants currently live. A common problem within these three basins is that most municipal, agricultural and industrial solid wastes, mixed with hazardous wastes (medical and sanitary), is dumped inside the basins, ending up accumulated along the coastline and then moving offshore to the island, and by association into the submarine environment. Also, ocean/waterway items such as engine oil containers, fiberglass, string and cord, and even an abandoned boat were observed. All these items remain in the environment for years (Buhl-Mortensen and Buhl-Mortensen, 2017). Marine anthropogenic litter found on Isla Arena reflects a strong influence from longshore-current transport. The wave-generated current patterns modeled under three scenarios suggest that MAL transport routes along the coast and the island are related to diffracted wavefronts approaching from NE and E (occasionally from N and NW). Those wave directions give rise to a dominant S-SW oriented longshore current that transport MAL along Isla Arena from NE/E to SW/W (Fig. 6). Pinzón et al. (1998), Anfuso et al. (2015) and Rangel-Buitrago et al. (2018) also observed this pattern for the Atlantico and Bolivar coastlines, and along the island, respectively. According to Williams et al. (2016a) and Rangel-Buitrago et al. (2018) the longshore transport combined with extreme runoff also produces the southward movement of significant MAL quantities called ‘litter blooms.’ These litter blooms can easily reach the island. Apart from the wave regime and longshore currents which controls MAL transport, the exposure of Isla Arena is considered equally important in its ability to retain or lose MAL. According to Gracia et al. (2018) and Rangel-Buitrago et al. (2018), exposed areas of the

2 = Mediocre, 3 = Unsatisfactory, 4 = Bad). These authors generated a weight table by means the Jenks optimization method for the identified MAL categories found (Table 2). Due to its proximity and similarities between litter typologies, the ES classification table can be applied using the data collected along Isla Arena (Table 2). Our data make clear that current amounts of all nine of the material typologies found are so elevated that Isla Arena can be classified as a coastal area with a bad environmental status (Table 2). The sector analysis developed confirms the above: Isla Arena presents considerable MAL magnitudes, which currently are negatively influencing cleanliness (CCI) and safety in terms of the presence of toxic and sharp MAL items (HII). Fig. 5 shows that both sides of the island are within the red area, which corresponds with dirty sectors that are profoundly altered by hazardous items. Along the island, current MAL amounts are too elevated for simple clean-up operations to succeed and restoration measures are necessary. Having identified the magnitudes, composition, and impacts of MAL along Isla Arena, two questions still remain: Where does MAL come from, and what is its delivery path to the island? Because Isla Arena is an uninhabited island and experiences little usage by boaters, all MAL found comes from sources that are located outside of the island. In that sense, the determination of MAL sources was addressed using each of the 55 MAL categories collected during the survey (Tables 1 and 3). Studies such as UNEP (2009), OSPAR (2009), Ocean Conservancy. (2010) and Veiga et al. (2016) suggests that specific MAL categories generally reflect specific sectors and activities (sources). In the same way, Topçu et al. (2013), Williams et al. (2016b) and Williams and Rangel-Buitrago (2019) highlight that MAL source determination can be easily achieved when specific items are found (e.g., syringes, blood containers, and tubes related to medical waste). Sources and activities that give rise to MAL found in Isla Arena are presented in Table 3. Our findings highlight that on Isla Arena, MAL mainly comes from land-based sources, and precisely the primary sources or generating activities can be found from nearby mainland river basins and beaches. Specifically, the five categories of MAL items that are the most dominant indicate the primary source of MAL was shoreline/tourism activities developed on the closest beaches, accounting for 60%. This value is close to the world average of 70% determined by the Ocean Conservancy (2018), and values obtained by Sciolo et al. (2016), Andrades et al. (2018) and Corraini et al. (2018) on some Brazilian and Caribbean islands. Dumping activities in the closest basins were the second most important MAL generator with a value of 24.6%. Ocean and waterway activities reach 9% while medical and sanitary waste and smoking activities together reach a value of 6.5%. Users of nearby beaches are identified as a critical MAL source, and are directly responsible for the decline of environmental quality of the beaches where they develop related activities as well the Isla Arena (see: Gracia et al., 2018; Rangel-Buitrago et al., 2018 and 2019a and b).

Table 3 Sources and activities with respective number of items, densities and percentages that give rise to MAL found on Isla Arena. SOURCE/ACTIVITY

Dumping Medical and Sanitary Waste Ocean/waterway Shoreline and Recreational Smoking-Related

TYPES OF MAL

LEEWARD

MAL derived from building and construction materials, tires, cars parts, drums, household trashes and appliances. Materials discarded into the sewer system, toilets, or left behind by beachgoers. Solid wastes from recreational fishing/boating, recreational/commercial fishing and shipping, and of oil and gas industry. Mainly littering by beachgoers, but also from waterside sports and those carried from streets, drains and gutters. Smoking-related packaging and materials.

Total

7

WINDWARD

TOTAL

N°

%

Density

N°

%

Density

N°

%

Density

136

26.10

0.54

217

23.72

0.87

353

24.6

0.706

26

4.99

0.10

60

6.56

0.24

86

6.0

0.172

45

8.64

0.18

84

9.18

0.34

129

9.0

0.258

314

60.27

1.26

547

59.78

2.19

861

60.0

1.722

0

0.00

0.00

7

0.77

0.03

7

0.5

0.014

521

100

2.084

915

100

3.66

1436

100

2.872

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Fig. 6. Wave-generated current patterns modeled under three scenarios suggest that MAL transport routes along the coast and Isla Arena are related to diffracted wave-fronts approaching from NE and E (occasionally from N and NW). Those wave directions give rise to a dominant SW oriented longshore current that transports MAL along Isla Arena from NE/E to SW/W.

Caribbean coast of Colombia can receive and thus accumulate more MAL amounts because they are under the direct influence of incoming NE-W waves. In the same way, wind circulation patterns along the island as well the entire Caribbean of Colombia are defined by the latitudinal migration of the Intertropical Convergence Zone (ITCZ). During the first seven months of the year (January–July) the ITCZ is south located, and this results in the generation of high and constant northeast trade winds (Rangel-Buitrago et al., 2018). After August, the ITCZ position is in the Northern Hemisphere, approximately over the Caribbean Sea. During this time of the year, low magnitude winds move over the equatorial zone from the Southern Hemisphere with variable directions. Specifically, winds have mean velocity values of 6–7 m/s and mainly come from the NE (50%) and the NNE (30%). Higher velocity values ranging from 6 to 11 m/s are associated with winds blowing from the NE during the dry period (December and April). For the rest of the year, winds blow from the E and with a typically low velocity, with values that fall below average (Anfuso et al., 2015). For the MAL issue on Isla Arena the question here is simple: How to solve a problem that is being generated far from this location? Identifying MAL hotspots is the starting-point on which stakeholders must focus, addressing effective litter management strategies (RangelBuitrago et al., 2017). If a specific activity is detected as the most contributing source of litter, managers should take an in-depth look into this activity and find/apply preventive strategies (e.g., educational and/or punitive measures). The premise here is simple: Removal comes after the fact in that litter is already there, accumulating daily. The better solution is to stop the litter from entering the beach environment. Here we focus on five activities (Table 3), especially on dumping, and shoreline and recreational activities that are responsible for 85% of all MAL found on Isla Arena. Clearly MAL accumulation is linked to careless human behavior

developed far from the island, and in that sense, strong environmental educational actions are needed. Behaviors are prime factors that determine whether people are living in an optimal interaction with the beach environment, and now, much research is focused on identifying what underlies current detrimental littering behaviors. Behavior change campaigns must have multiple targets for better results. These are placed as the best actions for long-term prevention and the improvement of the environmental awareness (Santos et al., 2005; Eastman et al., 2013; Rangel-Buitrago et al., 2017). The costs of such awareness programs, as well as waste management in general, must be borne by increased financial support from both the public and private sectors. For example in nearby mainland beaches, more than half of beachgoers come from the nearby cities of Cartagena and Barranquilla, and litter generation is highly correlated with fluctuations in population density and socioeconomic characteristics of beachgoers. Here, shoreline and recreational activities always have been and will be developed, which makes it necessary for the development of public awareness strategies to address the current and future litter issues. Litter found on Isla Arena also is related to marine-based sources (such as commercial fishing activities). Here, clean-ups should be the standard practice to be developed in the short term. However, environmental inspections need to be continually developed and enforced, particularly in the vicinity of the Magdalena River port. Enforcement of regulations such as the Annex V of MARPOL 73/78 convention must be taken seriously. Marine anthropogenic litter inputs can be chronic or acute, and sources can be at specific points or diffuse. To analyze trends in MAL composition and accumulation, the island must be monitored (Schulz et al., 2017, 2019). Also, visualizing patterns derived from monitoring activities will help to develop reduction initiatives, and to check if implemented management strategies are efficient. Currently, measures to curb MAL in nearby areas are restricted to 8

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study suggests five specific MAL sources wherein recreational activities over the mainland coastline and dumping activities over nearby river basins are responsible for the 84.5% of all MAL collected. The hazard of MAL on islands has been revealed by the elevated number of MAL accumulation in these locations over the last 20 years. The above highlights that the islands serve as sink areas for a large amount of MAL that comes from nearby coastlines. Furthermore, these island sinks are proxy indicators of the amount of litter within the adjacent marine environment, either as flotsam or submerged marine litter. Because a MAL degraded environment will experience a reduction of its ecological functions, it is mandatory to accelerate work on developing strategies to curbing the inexorable rise of MAL in these strategic environments. MAL management must be oriented on actions that eliminate or at least reduce MAL sources, and activities that are developed on nearby sites in order to avoid more MAL arrivals to the island. The marine anthropogenic litter issue on Isla Arena as well nearby areas needs urgent and clever solutions. Proactivity is the key. Flexible strategies should be adopted to begin real MAL management, and thus improve the island's environmental quality.

Fig. 7. Proposed steps involved in an integrated marine anthropogenic litter management strategy.

the presence of some collection bins, and sporadic beach cleanups developed on specific sites. Unfortunately, litter collection from bins and beach cleanups are particular activities of the holiday season, despite the whole beach being open and used for recreational and artisanal fishing year-round. The trash bins alone are not the solution to problem. A typical situation in the area is that high winds often remove litter from the bins, reintroducing it into the beach environment, and then is subject to marine transport to the island. Previous studies developed in the area by Williams et al. (2016a), Gracia et al. (2018) and RangelBuitrago et al. (2019a) highlighted the same situation, and called attention to the need for more trash bins for beach use. For an optimal beach litter management, targeted strategies should include the establishment of real goals, a balance of clear priorities, and mutually reinforcing measures with a short-term impact, as well cost-effective measures with a long-term- impact (Marais and Armitage, 2004; Diez et al., 2019). An integrated litter management strategy would typically involve three steps (Fig. 7):

Acknowledgements This work is a contribution to research groups: “Geology, Geophysics and Marine - Coastal Process”, Universidad del Atlántico (Colombia), and “Department of Geology”, Grand Valley State University (USA). References Agustin, A.E., Merrifield, M.A., Potemra, J.T., Morishige, C., 2015. Temporal variability of marine debris deposition at tern island in the northwestern Hawaiian islands. Mar. Pollut. Bull. 101, 200–207. Alkalay, R., Pasternak, G., Zask, A., 2007. Clean-coast index—a new approach for beach cleanliness assessment. Ocean Coast Manag. 50, 352–362. Al-Najjar, T., Al-Shiyab, A., 2011. Marine litter at (Al-Ghandoor area) the most northern part of the Jordanian coast of the Gulf of Aqaba, Red Sea. Nat. Sci. 3, 921–926. Andrades, R., Santos, R., Joyeux, J.-C., Chelazzi, D.,, Cincinelli, A., Giarrizzo, T., 2018. Marine debris in trindade island, a remote island of the south atlantic. Mar. Pollut. Bull. 137, 180–184. Anfuso, G., Rangel-Buitrago, N., Correa, I., 2015. Evolution of sandspits along the Caribbean Coast of Colombia: natural and human influences. In: Randazzo, G., Jackson, D., Cooper, J.A. (Eds.), Sand and Gravel Spits. Springer, New York, pp. 1–21. Angiolillo, M., 2019. Debris in deep water. In: Shepard, C. (Ed.), World Seas: an Environmental Evaluation. Elsevier, Amsterdam, pp. 251–268. Bergmann, M., Gutow, L., 2015. Marine Anthropogenic Litter. Springer International Publishing, Berlin. Bosence, D., 2005. A genetic classification of carbonate platforms based on their basinal and tectonic settings in the Cenozoic. Sediment. Geol. 175 (1–4), 49–72. Buhl-Mortensen, P., Buhl-Mortensen, L., 2017. Impacts of bottom trawling and litter on the seabed in Norwegian waters. Front. Mar. Sci. 5, 42. Campbell, J., Barnett, J., 2010. Climate Change and Small Island States, Power, Knowledge and the South Pacific. Routledge, London. Campbell, M., Peters, L., McMains, C., Cruz, M., Sargisson, R., Blackwell, Hewwitt, 2019. Are our beaches safe? Quantifying the human health impact of anthropogenic beach litter on people in New Zealand. Sci. Total Environ. 651, 2400–2409. Corbin, C.J., Singh, J.G., 1993. Marine debris contamination of beaches in St. Lucia and Dominica. Mar. Pollut. Bull. 26 (6), 325–328. Corraini, N., de Souza de Lima, A., Bonetti, J., Rangel-Buitrago, N., 2018. Troubles in the paradise: litter and its scenic impact on the North Santa Catarina island beaches, Brazil. Mar. Pollut. Bull. 131, 572–579. Davidson-Arnott, R., 2010. Introduction to Coastal Processes and Geomorphology. Cambridge, London. Davis, R., Fitzgerald, D., 2004. Beaches and Coasts. Blackwell Science, London. Derraik, J., 2002. The pollution of the marine environment by plastic debris: a review. Mar. Pollut. Bull. 44, 842–852. Diez, S.M., Patil, P.G., Morton, J., Rodriguez, D.J., Vanzella, A., Robin, D.V., Maes, T., Corbin, C., 2019. Marine Pollution in the Caribbean: Not a Minute to Waste. World Bank Group, Washington, D.C. Eastman, L.B., Núñez, P., Crettier, B., Thiel, M., 2013. Identification of self-reported user behavior, education level, and preferences to reduce littering on beaches – a survey from the SE Pacific. Ocean Coast Manag. 78, 18–24. Ellis, E., Goldewijk, K., Klein, S., Siebert, S., Lightman, D., Ramankutty, N., 2011. Anthropogenic transformation of the biomes 1700 to 2000. Glob. Ecol. Biogeogr. 19 589-60. Gall, S.C., Thompson, R.C., 2015. The impact of debris on marine life. Mar. Pollut. Bull.

• Analytics. • Policy updates and reforms. • Investments. The scale of these three steps ranges from local to national to regional. Also, these steps must be aligned with relevant international and regional mandates. According to Williams and Rangel-Buitrago (2019), adequate litter management begins with an accurate characterization of magnitudes, extension, sources, and impacts of litter (detailed knowledge of the problem). Once the typology and dynamics of litter are known, stakeholders may correctly intervene in the management practices to be developed. The imperative is to remember that any management decision needs to be based on reliable scientific information. Therefore, regular collection of data on litter, its sources, and how this litter affects marine habitats, local economies, and populations needs to be improved at the local, regional and national levels. Similarly, enforcement must be implemented at all of these levels of government. This baseline is a snapshot that shows the MAL abundance and related impacts on the fragile environment of Isla Arena, located on the central part of the Caribbean of Colombia. Current MAL magnitudes which reach an average of 2.87 items/m2, severely impacting environmental variables such as CCI, HII, and ES, making clear that this island is now under a severe litter problem that must be solved. Marine anthropogenic litter typology found, as well the “uninhabited” status of the area, confirms that all items currently polluting the island are not from a local origin, but come from far sources. In the same way, this 9

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Great Britain. Philos. Trans. Royal Soc. A. 369, 1056–1084. Rangel-Buitrago, N., Anfuso, G., Correa, I., Ergin, A., Williams, A.T., 2013. Assessing and managing scenery of the caribbean coast of Colombia. Tour. Manag. 35, 41–58. Rangel-Buitrago, N., Williams, A., Anfuso, G., Arias, M., Gracia, A., 2017. Magnitudes, sources, and management of beach litter along the Atlantico Department coastline, Caribbean coast of Colombia. Ocean Coast Manag. 138, 142–157. Rangel-Buitrago, N.G., Williams, A., Anfuso, G., 2018. Killing the goose with the golden eggs: litter effects on scenic quality of the Caribbean coast of Colombia. Mar. Pollut. Bull. 127, 22–38. Rangel-Buitrago, N., Velez, A., Gracia, A., Mantilla, E., Arana, V., Trilleras, J., ArroyoOlarte, H., 2019a. Litter impacts on cleanliness and environmental status of Atlantico department beaches, Colombian Caribbean coast. Ocean Coast Manag. 179, 104835. Rangel-Buitrago, N., Williams, A.T., Ergin, A., Anfuso, G., Micallef, A., Pranzini, E., 2019b. Coastal scenery: an introduction. In: Rangel-Buitrago, N. (Ed.), Coastal Scenery: Evaluation and Management. Springer, Amsterdam, pp. 1–16. Rangel-Buitrago, N., Vergara-Cortez, H., Barria-Herrera, J., Contreras-Lopez, M., Agredano, R., 2019c. Marine debris occurrence along Las Salinas beach, Viña del Mar (Chile): magnitudes, impacts and management. Ocean Coast Manag. 171, 104842. Ratter, B., 2018. Geography of Small Islands. Springer. Rech, S., Macaya-Caquilpan, V., Pantoja, J.F., Rivadeneira, M.M., Madarriaga, D.J., Thiel, M., 2014. Rivers as a source of marine litter – a study from the SE Pacific. Mar. Pollut. Bull. 82, 66–75. Rech, S., Salmina, S., Borrell, Y., Garcia-Vasquez, E., 2018. Dispersal of alien invasive species on anthropogenic litter from European mariculture areas. Mar. Pollut. Bull. 131, 10–16. Ríos, N., Frias, J.P.G.L., Rodríguez, Y., Carriço, R., Garcia, S.M., Juliano, M., Pham, C.K., 2018. Spatio-temporal variability of beached macro-litter on remote islands of the North Atlantic. Mar. Pollut. Bull. 133, 304–311. Royle, S.A., 2014. Islands: Nature and Culture. Reaktion, London. Santos, I.R., Friedrich, A.C., Barreto, F.P., 2005. Overseas garbage pollution on beaches of northeast Brazil. Mar. Pollut. Bull. 50, 782–786. Schulz, M., Neumanm, D., Fleet, D., Matthies, M., 2013. A multi-criteria evaluation system for marine litter pollution based on statistical analyses of OSPAR beach litter monitoring time series. Mar. Environ. Res. 92, 61–70. Schulz, M., van Loon, W., Fleet, D.M., Baggelaar, P., van der Meulen, E., 2017. OSPAR standard method and software for statistical analysis of beach litter data. Mar. Pollut. Bull. 122, 166–175. Schulz, M., Walvoort, D.J.J., Barry, J., Fleet, D.M., van Loon, W.M.G.M., 2019. Baseline and power analysis for assessment of beach litter reductions in the European OSPAR region. Environ. Pol. 248, 555–564. Sciolo, T., Mijts, E., Becker, T., Epping, M., 2016. Beach debris on Aruba, Southern Caribbean: attribution to local land-based and distal marine-based sources. Mar. Pollut. Bull. 106, 49–57. Stachowitsch, M., 2019. The Beachcomber's Guide to Marine Debris. Springer, Amsterdam. Topçu, E.N., Tonay, A.M., Dede, A., Öztürk, B., 2013. Origin and abundance of marine litter along sandy beaches of the Turkish Western Black Sea Coast. Mar. Environ. Res. 85, 21–28. UNEP, 2009. Sustainable Coastal Tourism – an Integrated Planning Management Approach. United Nations Environment Programme, Milan. Veiga, J.M., Vlachogianni, T., Pahl, S., Thompson, R.T., Kopke, K., Doyle, T., Hartley, B., Maes, T., Orthodoxou, D., Loizidou, X., Alampei, I., 2016. Enhancing public awareness and promoting co-responsibility for marine litter in Europe: the challenge of MARLISCO. Mar. Pollut. Bull. 102, 309–315. Williams, A.T., Micallef, A., 2009. Beach Management Principles and Practice. Earthscan, London. Williams, A.T., Rangel-Buitrago, N., Anfuso, G., Cervantes, O., Botero, C., 2016a. Litter impacts on scenery and tourism on the Colombian north Caribbean coast. Tour. Manag. 55, 209–224. Williams, A.T., Randerson, P., Di Giacomo, C., Anfuso, G., Macias, A., Perales, J.A., 2016b. Distribution of beach litter along the coastline of Cádiz, Spain. Mar. Pollut. Bull. 107 (1), 77–87. Williams, A.T., Rangel-Buitrago, N., Pranzini, E., Anfuso, G., 2018. The management of coastal erosion. Ocean Coast Manag. 156, 4–20. Williams, A.T., Rangel-Buitrago, N., 2019. Marine Litter: solutions for a major environmental problem. J. Coast. Res. 35 (3), 648–663. Zalasiewicz, J., Waters, C., do Sul, I., Corcoran, P., Barnosky, A., Cearreta, A., Edgeworth, M., Galuszca, A., Jeandel, C., Leindelder, R., McNeill, J.R., Steffen, W., Summerhayes, C., Wagreich, M., Williams, M., Wolfe, A., Yonan, Y., 2016. The geological cycle of plastics and their use as a stratigraphic indicator of the Anthropocene. Anthropocene 13, 4–17.

92, 170–179. Gracia, A., Sellanes, J., Rangel-Buitrago, N., 2012. Methane seep molluscs from the sinusan jacinto fold belt in the Caribbean Sea of Colombia. J. Mar. Biol. Assoc. U. K. 92 (6), 1367–1377. Gracia, A., Rangel-Buitrago, N., Florez, P., 2018. Beach litter and woody-debris colonizers on the Atlantico department Caribbean coastline, Colombia. Mar. Pollut. Bull. 128, 185–196. Hardesty, B.D., Lawson, T.J., van der Velde, T., Lansdell, M., Wilcox, C., 2016. Estimating quantities and sources of marine debris at a continental scale. Front. Ecol. Environ. 15, 18–25. Hidalgo-Ruz, V., Thiel, M., 2013. Distribution and abundance of small plastic debris on beaches in the SE Pacific (Chile): a study supported by a citizen science project. Mar. Environ. Res. 87–88, 12–18. IUCN, 2019. Red List of Species. accessed. https://www.iucnredlist.org/search, Accessed date: 18 March 2019. Ivar do Sul, J.A., Costa, M.F., 2007. Marine debris review for Latin America and the Wider Caribbean Region: from the 1970s until now, and where do we go from here? Mar. Pollut. Bull. 54, 1087–1104. Kueffer, C., Keaohanuiopuna, K., 2017. What is the importance of islands to environmental conservation? Environ. Conserv. 44 (4), 311–322. Langford, E., 2006. Quartiles in elementary statistics. J. Stat. Educ. 14 (3), 1–6. Lavers, J., Bond, A., 2019. Exceptional and rapid accumulation of anthropogenic debris on one of the world's most remote and pristine islands. Proc. Natl. Acad. Sci. 114 (23), 6052–6055. Lavers, J., Bond, A., 2017. Exceptional and rapid accumulation of anthropogenic debris on one of the world's most remote and pristine islands. Proc. Natl. Acad. Sci. 114 (23), 1–4. Lavers, J.L., Dicks, L., Finger, A., 2019. Significant plastic accumulation on the cocos (keeling) islands, Australia. Sci. Rep. 9, 7102. Leatherman, S., Beller-Simms, N., 1997. Sea-Level rise and small island states; an overview. J. Coast. Res. 24 (3), 1–16. Lebreton, L.C.M., Zwet, J., Damsteeg, J.-W., Slat, B., Andrady, A., Reisser, J., 2018. River plastic emissions to the world's oceans. Nat. Commun. 8, 15611. Marais, M., Armitage, N., 2004. The measurement and reduction of urban litter entering stormwater drainage systems: paper 2 – strategies for reducing the litter in the stormwater drainage systems. Water S.A. 30 (4), 483–492. Masselink, G., Hughes, M.G., 2003. An Introduction to Coastal Processes and Geomorphology. Routledge, London. Maximenko, N., Hafner, J., Niiler, P., 2012. Pathways of marine debris derived from trajectories of Lagrangian drifters. Mar. Pollut. Bull. 65, 51–62. Menard, W., 1986. Islands. Scientific American, Washington, DC. Novotny, T.E., Lum, K., Smith, E., Wang, V., Barnes, R., 2009. Cigarettes butts and the case for an environmental policy on hazardous cigarette waste. Int. J. Environ. Res. Public Health 6, 1691–1705. Nurse, L.A., Sem, G., Hay, J.E., Suarez, A.G., Wong, P.P., Briguglio, L., Ragoonaden, S., 2001. Small island states. In: McCarthy, J.J., Canziani, O.F., Leary, N.A., Dokken, D.J., White, K.S. (Eds.), Climate Change 2001: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Third Assessment of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, UK and New York, NY, USA, pp. 843–876. Ocean Conservancy, 2010. Trash Travels – 2010 Annual Report. Washington, DC. https://oceanconservancy.org/wp-content/uploads/2017/04/2010-OceanConservancy-ICC-Report.pdf, Accessed date: 5 December 2018. Ocean Conservancy, 2018. International Coastal Cleanup. https://oceanconservancy. org/trash-free-seas/international-coastal-cleanup/past-results, Accessed date: 18 March 2019. OSPAR, 2009. Marine Litter in the North-East Atlantic Region: Assessment and Priorities for Response. OSPAR, London. OSPAR, 2010. Guideline for Monitoring Marine Litter on the Beaches in the OSPAR Maritime Area. OSPAR, London. Philipp, R., Pond, K., Rees, G., 1991. Research and the problems of litter and medical wastes on the UK coastline. Br. J. Clin. Pract. 51 (3), 164–168. Pieper, C., Ventura, M.A., Martins, A., Cunha, R.T., 2015. Beach debris in the Azores (NE atlantic): faial island as a first case study. Mar. Pollut. Bull. 101 (2), 575–582. Pilkey, O.H., Cooper, A.G., 2014. The Last Beach. Duke University Press, Durham. Pilkey, O., Neal, W.J., Kelley, J., Cooper, A., 2011. The World's Beaches: a Global Guide to the Science of the Shoreline. University of California Press, Berkley. Pinzón, J., Perdomo, A., Diaz, J.M., 1998. Isla Arena, una formación coralina saludable en el area de influencia de la pluma del Rio Magdalena Plataform continental del Caribe Colombiano. Bol. Invest. Mar. Costeras 27, 21–37. Price, S.J., Ford, J.R., Cooper, A.H., Neal, C., 2011. Humans as major geological and geomorphological agents in the Anthropocene: the significance of artificial ground in

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