Geoforum 86 (2017) 188–191
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Critical review
Environmental and social aspects of underwater logging ⁎
MARK
Haris R. Gilani , John L. Innes Department of Forest Resources Management, University of British Columbia, 2424 Main Mall, Vancouver, British Columbia V6T 1Z4, Canada
A R T I C L E I N F O
A B S T R A C T
Keywords: Underwater logging Rediscovered wood Submerged forests Reservoirs Large woody debris
Underwater logging is a relatively new concept in forestry that has significant economic benefits but also consequences for the environment and local communities. Underwater logging has traditionally been undertaken by divers. However, safety concerns mean that conventional harvesting methods using divers need to be replaced by more sophisticated mechanized harvesting techniques. This paper outlines the environmental and social aspects of underwater logging, highlighting issues that must be considered before any underwater harvesting operations are executed. While the economic reasons for harvesting underwater logs seem compelling, as do the associated social benefits, such as employment generation, there are significant environmental impacts of removing trees from reservoirs, as submerged trees serve as important ecological habitat for aquatic life. Due to the absence of any regulatory regimes encompassing underwater logging, we propose best-practice guidelines for underwater logging operations and suggest the need for a comprehensive sustainability framework based on internationally recognized criteria and indicators to ensure underwater logging operations are environmentally safe, socially beneficial and economically viable.
1. Introduction Over the last 100 years, many countries have invested in hydroelectric power to meet their ever-increasing energy demands and, as a result, large tracts of forested land have been flooded by the creation of large dams developed for hydroelectric power (Tenenbaum, 2004). In many cases, trees were not removed prior to flooding. Lucas (2007) has argued that the time required to plan and build a dam, which is usually between two to five years, is shorter than the time required to harvest the large amounts of timber available in some of these forests, which explains why timber with considerable economic value is often flooded. In some countries, appropriate harvesting technology was unavailable at the time of dam construction, and in many cases, the tree species were considered undesirable and the loss was deemed acceptable. For example, in Tasmania, Australia, the site of Pieman Lake was opened up to forestry to avoid wasting the timber. However, the region’s dense forest and inaccessible nature made logging difficult and by the time the area was ready to be flooded, only a small portion of the lake’s footprint had been logged, resulting in the remaining forest being flooded. In Brazil, it is estimated that only 1% of the above-ground biomass was removed prior to the flooding of Tucuruí Lake (Fearnside, 1997), drowning a major timber resource. The World Commission on Dams (2000) estimated that more than 45,000 large reservoirs were in place by the end of 20th century, many of which contained submerged forests. An example of a large reservoir ⁎
containing a drowned forest is provided by the Nechako reservoir in northern British Columbia, constructed in 1952. After displacing First Nations people from their land, a private company reversed the flow of a river, creating a new lake estimated to contain 15 million trees (Randalls and Petrokofsky, 2014). Crockford (2008) has estimated the value of submerged forests globally to be approximately $50 billion, with new areas continuing to be flooded. Underwater wood recovery is not a new phenomenon, and salvage loggers have for many decades recovered lost logs from lakes, rivers and major waterways. Salvage logging enterprises were particularly focused on the recovery of logs lost while being floated down rivers. These were mostly located in areas where there had been significant use of watertransportation by logging companies. Drowned logs, sunken trees, and wood from building demolition are all considered “rediscovered wood” and some argue that rediscovered wood could contribute to meeting international wood demand (Tenenbaum, 2004). A more recent innovation is to harvest trees that have been flooded during dam construction, a process known as underwater logging. This generally takes place in still water. In some cases, the crowns of the trees remain above water whereas in others the entire tree is underwater. In all cases, the trees die but decay underwater can be slowed dramatically by the anaerobic environment. The interest in underwater harvesting comes from eliminating hazards to shipping and the untapped supply of high-valued species, such as old growth red cedar and tropical hardwoods (Milne et al., 2013). The potential of underwater
Corresponding author. E-mail address:
[email protected] (H.R. Gilani).
http://dx.doi.org/10.1016/j.geoforum.2017.09.018 Received 8 June 2017; Received in revised form 22 September 2017; Accepted 24 September 2017 0016-7185/ © 2017 Published by Elsevier Ltd.
Geoforum 86 (2017) 188–191
H.R. Gilani, J.L. Innes
of the alveolar air sacs due to unsafe diving practices (Rozali et al., 2006). Although divers’ certification is required for underwater loggers in North America and other Western countries, in many developing countries, including Panama and Malaysia, many industrial diving activities are unregulated and underwater loggers may have no prior diving training. Added to this, the use of faulty breathing equipment is not uncommon (Halim, 2004). Underwater divers are also exposed to the risk of developing decompression illnesses (DCI), a condition that is developed from formation of bubbles in the tissues or circulation system as a result of inadequate elimination of inert gas (nitrogen) after a dive (Zin and Sulaiman, 2008). Although accurate figures are not available for the incidence of such problems with divers performing underwater logging; Loke et al. (1998) reported six cases of DCI in underwater loggers in Malaysia from March 1994 to August 1996, including two fatalities.
Table 1 Important underwater logging operations in reservoirs around the world. Country
Reservoir
Reservoir area
Year of logging operations
Reference
Canada USA Surinam
890 km2 16.23 km2 12,200 km2
1970 1991 2004
Klotz (1975) McLean (1991) BWWI (2017)
Brazil Panama
Lake Ootsa Lake Cushman Lake Brokopondo Lake Tucurui Lake Bayano
2247 km2 350 km2
1987 2010
Ghana Australia
Lake Volta Lake Pieman
8502 km2 2653 km2
2008 2015
Malaysia
Lake Kenyir
260 km2
1991
Fearnside (1997) Randalls and Petrokofsky (2014) Fitzgerald (2008) HydroWood (2017) Loke et al. (1998)
2.2. Mechanized underwater logging
logging has been recognized by a number of states across the world, and countries, such as Canada, the United States, Panama, Brazil, Australia, Ghana and Malaysia, have begun to exploit this resource (Table 1). Proponents of underwater logging argue that the negative effects associated with deforestation could be reduced significantly through the harvesting of flooded timber resources (Lucas, 2007). However, in some cases, the human population displaced by the construction of the reservoir would have continued to clear forests in the inundated area had the reservoir not been created, and some logging activities may have been displaced to forests outside the submergence area (Fearnside, 1997). Other advantages of underwater logging include the direct and indirect social and economic benefits, including improvement in lake transportation safety, recovery of the fibre value of an otherwise lost resource, and creation of jobs and training opportunities for local communities (Asare and Helmus, 2012). With continuing dam construction, especially in South-East Asia and Brazil, the amount of flooded forest is growing, increasing the number of potential underwater logging sites (Randalls and Petrokofsky, 2014). The greatest potential downside to underwater logging is facing customers’ concerns about how the wood is harvested in underwater logging projects (Greenemeier, 2005). While with terrestrial logging such concerns can be assuaged through third-party certification systems, increased social and environmental expectations point to a growing need for reservoir managers and owners to understand and address the challenges and opportunities posed by submerged forests. Underwater logging is not addressed in current forest management certification schemes. Despite underwater logging being an innovative industry with considerable social and environmental implications, it has received very little attention in the academic literature. Here, we summarize what is known about the environmental and social aspects of underwater logging. We examine the harvesting techniques that have been adopted, and use examples of various underwater logging projects in the world to shed light on its environmental and social aspects. Finally, we propose best-practice guidelines for underwater logging operations that could serve as a reference for operators in mitigating risks associated with underwater logging operations.
One of the earliest attempts to salvage underwater logs from a reservoir took place in British Columbia in 1970 in Lake Ootsa, utilizing a self-propelled barge equipped with a grapple (Klotz, 1975). More recently, in an attempt to reduce the safety hazards to divers and related unsafe diving practices, Triton Logging, a Canadian entity, developed specialized machinery called the Sawfish to harvest underwater trees (Milne et al., 2013). The Sawfish harvester is designed to work entirely underwater. The Sawfish system uses air bags that are attached to submerged logs so that the log is brought to the surface after being cut. The sawfish uses biodegradable vegetable-oil-based hydraulic fluids to minimize water pollution during salvage operations (Tenenbaum, 2004). 3. Enviornmental and social aspects of underwater logging 3.1. Environmental aspects Concerns have been raised about the environmental and social impacts of underwater logging projects. Although only a few studies have examined the habitat value of snags, the ecological importance of submerged logs and large woody debris (LWD) has been well-documented (Linohss et al., 2012; Shields et al., 2004). In natural environments, submerged logs are particularly important as habitat that forms the basis of aquatic food webs, especially where invertebrate diversity, abundance, biomass, and productivity are important (Linohss et al., 2012). LWD has been shown to enhance habitat and hydraulic complexity (Kaeser and Litts, 2008), to regulate fungal communities (Tsui et al., 2000), and to trap and retain organic matter (Raikow et al., 1995). In addition, it provides cover and refuges that reduce predation risks (Crook and Robertson, 1999), and in river channels, it mediates channel-forming processes, such as sediment transport and deposition (Montgomery and Piégay, 2003). Although most research literature shows that the routine clearance of wood from water courses is not consistent with maintenance of healthy aquatic ecosystems, within Europe LWD accumulations are generally seen as a river management problem and are routinely cleared from river channels (Piégay and Gurnell, 1997). While the value of LWD in streams has been well-documented, the value in still water is less certain, particular at depth. Even less information is available for artificial situations, such as reservoirs that have not had much time to develop mature aquatic ecosystems. As a result, it is difficult to determine whether the information obtained from fluvial systems can be applied to the lacustrine environment, and some aspects are clearly different. Due to their value and the impacts associated with harvesting submerged trees, a permit is required in most countries before the recovery of submerged timber can proceed. However, once an underwater logging operator has secured the appropriate authorization from the government or resource owner, there
2. Harvesting methods 2.1. Commercial divers The conventional way to extract submerged underwater logs has been to hire divers to operate chainsaws underwater. However, the method of using divers is both dangerous and expensive (Tenenbaum, 2004). Previous studies have reported Pulmonary Overinflation Syndrome in underwater loggers, which is a group of barotrauma-related diseases caused by the expansion of gas trapped in the lungs, or over pressurization of the lungs with subsequent overexpansion and rupture 189
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Table 2 Summary of underwater logging issues and proposed guidelines. Issues Operational
Harvesting
Environmental
Social
Guidelines a. b. c. d. a. b. c. d. a. b. c. d. a. b. c. d.
Full surveys of the extent of the resource should be undertaken prior to the start of logging operations (G) Ecologically sensitive areas should be designated and excluded from harvesting plans (G) Legal authorizations such as permits, concessions, and deeds should be in place (L) Local communities and/or Indigenous groups with legal or customary resource use rights should maintain control over log recovery operations (L) Use of divers should be minimized (L) Any divers should be fully trained and in possession of commercial diving certification (G) Worker safety conditions associated with the underwater logging operation should meet legal requirements (L) Appropriate safety equipment, including life jackets, first aid equipment, and chainsaw proof chaps should be available (G) Environmental impacts associated with log recovery and on and off-site processing should be identified and mitigated (G) No logging should be undertaken in the littoral zone of reservoirs (G) Root systems of submerged trees should not be disturbed (G) Vegetable-based oils and hydraulic fluids should be used (G) Where possible, logs should be processed locally (L) Local communities should be given opportunities in terms of employment, training, and other work-related benefits (G) Local fishers and other stakeholders should be given an opportunity to participate in planning of operations and consulted on potential impacts (L) Any cultural or historic impacts of the underwater logging operations should be identified and reconciled (L)
G denotes general guidelines and L denotes guidelines that depend on the local situation.
debates that can generate more proactive, preventative and socially relevant decision making (Eden, 2009). The shift of public authority to delegate social and environmental regulation to the private sector has often led to the establishment of ‘voluntary’ standards and certifications on sustainability (Ponte, 2014). Within the broad field of private authority, the study of sustainability standards and certifications has received much scholarly attention. Research in geography into certification is now developing with several authors focusing on certification (e.g. Morris and Dunne, 2004; Klooster, 2010). These studies examined various aspects of certification including the impact of certification on forest products and standard-setting processes. The legitimacy of certification as an authoritative governance mechanism has been emphasized in both political science and human geography literature (Cashore et al., 2004; McDermott, 2012). The expanding number of underwater logging operations and the inconsistencies in the operating procedures have often led to concerns among stakeholders. In today’s market, there is an increasing demand for reassurance about how products are being made, where they are sourced from, what the environmental consequences are of the way they are produced, and how they are disposed of when their life cycle is finished (Humphrey, 2001). This is especially the case with respect to products that draw on underwater timber resources where the extraction process may threaten the aquatic habitat. Here, we propose guidelines for underwater logging operations that might serve as a starting point for informing operators about the important issues involved in underwater logging operations (Table 2). These guidelines will also set the basis towards establishing underwater logging certification standards. Underwater logging operations should follow these best-practice guidelines, until standardization has been fully accomplished.
is often no limit to the number of logs that may be recovered within a specified time period. For example, a private company was awarded a permit covering 350,000 hectares of Volta Lake for 25 years by the Government of Ghana. 3.2. Social aspects Resource harvesting and extraction, whether they involve minerals, timber, or agricultural products, have social consequences (Kusel, 2001). In the case of underwater logging, the resource is generally under the jurisdiction of the state or the local government that issues permits to operators to extract trees. The agreements usually specify that all trees will be removed, making the species mix unimportant (Randalls and Petrokofsky, 2014). Concessions often involve social goals, such as improved safety of boat transportation; with the creation of reservoirs located in populated areas has often resulted in the development of transportation corridors, recreational venues and economic drivers. Vessels – including ferries, canoes or fishing boats – are at risk of hitting submerged or partially submerged trees and fluctuating water levels increase these risks. Each year, hundreds of fatalities are reported in large, tree-filled reservoirs with underdeveloped marine safety provisions. For example, the Ghana Maritimes Authority reported 386 fatalities in various accidents in Lake Volta between 1990 and 2012, and one of the main causes was the capsizing of boats after hitting snags (Sumabe, 2013). Other social benefits include employment generation for local communities, as the harvesting creates job opportunities not only with logging operations but also at any resulting processing plants. For example, an underwater logging project in Lake Bayano in Panama generated employment opportunities for the indigenous Kuna nation. Gordon and Amatekpor (1999) reported that the construction of the dam on the Volta River that created the Volta Lake forced the relocation of some 80,000 people to 52 newly created towns on the Lake’s higher banks and the resettlement program created socio-economic problems, which had an impact on the physical and mental health, safety and well-being of the settlers. However, the removal of obstructions that could affect fishing nets could be seen as a positive social aspect of underwater logging as the fishing nets were easily entangled in submerged trees.
4. Conclusions and future direction The increased global demand for wood products, environmental impacts associated with terrestrial logging and deforestation, and economic opportunities are driving companies to invest in underwater logging in several countries across the globe. Clearly, there are safety concerns associated with underwater logging, especially when divers are employed to harvest the trees using chainsaws. In response to these safety concerns, sophisticated technologies have been introduced to harvest trees mechanically that eliminate the need to use diver-based logging techniques. Logs are removed from water bodies primarily for their economic value but social benefits such as safety, navigation and employment generation are increasingly being linked with underwater logging. The environmental values associated with submerged logs illustrate the importance of submerged trees to fish and fish food
3.3. Guidelines for underwater logging In recent years there has been a shift from government to governance, and closed debates and state-led, reactive and technocratic decision making has become more transparent through the stakeholder-led 190
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