Ghost Fishing Research Articles

Diagnosis and Treatment of Pulmonary Disease in Sea Turtles (Caretta caretta).

Simple SummaryEvaluation of the respiratory system is a critical aspect of sea turtle medicine due to their peculiar anatomy. The location of the lungs under the carapace makes them vulnerable to wounds involving the carapace, which are frequent and significant complications of vessel strike injuries. Open lung wounds result in aspiration, loss of buoyancy control, and secondary infection. In sea turtles, pulmonary diseases can originate from many causes. Increased marine pollution is reflected in the increasing occurrence of sea turtles with entanglement injuries around the neck or flippers, caused by plastic waste, ghost nets, fishing lines, etc. These injuries may directly damage the upper airway or create life-threatening secondary infections. The object of the study was to describe clinical signs, radiographic, endoscopic and computed tomography examinations, and cytological and microbiological findings useful to obtaining an accurate diagnosis of pulmonary diseases in sea turtles. Moreover, we describe the treatment carried out on the basis of antimicrobial susceptibility testing to avoid unnecessary treatments and antibiotic-resistance phenomenon. Data were collected from 14 turtles. Radiographic signs of pulmonary pathology were seen in all cases. Four sea turtles underwent advanced diagnostic investigations so as to better characterize the pulmonary pattern. The bronchoalveolar lavage allowed us to withdraw fluid from the lower airways and to perform cytological and bacteriological examinations on all 14 subjects. The study suggests how it may be useful to implement diagnostic procedures in order to obtain an accurate and early diagnosis, to prevent unnecessary therapy, and to contain antibiotic-resistance phenomena.The aim of this study was to describe the clinical signs, radiographic, endoscopic and CT findings, cytological and microbiological findings and treatments of pulmonary diseases in sea turtles, in order to obtain an accurate diagnosis that avoids unnecessary therapy and antibiotic-resistance phenomena. In total, 14 loggerheads (Caretta caretta), with clinical and/or radiographic findings of pulmonary pathology, were assessed through various combinations of clinical, radiological, CT, endoscopic examination and bronchoalveolar lavage, which recovered fluid for cytologic and microbiologic analysis. In all cases, radiographic examination led to a diagnosis of pulmonary disorders—4 unilateral and 10 bilateral. All bacteria cultured were identified as Gram-negative. Antibiotic resistance was greater than 70% for all beta-lactams tested. In addition, all bacterial strains were 100% resistant to colistin sulfate and tetracycline. Specific antibiotic therapies were formulated for seven sea turtles using Enrofloxacin, and for four sea turtles using ceftazidime. In two turtles, antibiotic therapy was not included due to the presence of antibiotic resistance against all the antibiotics evaluated. In both cases, the coupage technique and environmental management allowed the resolution of the lung disease without antibiotics. All 14 sea turtles were released back into the sea. Radiographic examination must be considered the gold standard for screening sea turtles that show respiratory signs or abnormal buoyancy. Susceptibility testing with antimicrobials allowed appropriate therapy, including the reduction of antibiotic-resistance.

Artisanal fisher perceptions on ghost nets in a tropical South Atlantic marine biodiversity hotspot: Challenges to traditional fishing culture and implications for conservation strategies

Ghost fishing, the ability of fishing equipment to continue to capture organisms even after it is no longer controlled, leads to serious marine impacts, including bycatch, which contributes to biodiversity loss. Insistent complaints from artisanal fisher in the state of Bahia, Brazil, concerning the impacts of nets lost or abandoned by fisher from other regions that operate in their traditional fishing territory were brought to the attention of our research group. Therefore, this study aims to describe the knowledge and classify fisher perceptions in south Bahia regarding ghost fisheries in the region, as well as the resulting impacts and fisher ideas for solving this problem in a coastal coral reef region. Semi-structured interviews were conducted between August 2015 and September 2017 with 60 fishers, 59 men and one woman, that fish with hand lines and hooks in the studied area. A total of 90% of respondents (n = 54) reported having found ghost nets in their ancestral fishing territories, while 93% (n = 56) associated ghost nets with financial losses and marine environment impacts. Most respondents (n = 56; 93%) also indicated lower fishery yields due to ghost nets and indicated (n = 55; 91.9%) that most ghost nets found in the area are used for lobster fishing, which is banned in Brazil. Fishers revealed an active interest in solving this socio-environmental problem, demonstrating detailed knowledge related to the loss of fishing nets in the local marine environment, as they have been finding and removing ghost nets from the local sea. Fisher's ideas to solve this problem included the implementation of fines for fishers caught in breach of regional and national fisheries regulations, and management actions, such as ghost net removal from the sea. Establishing partnerships between fisher and the federal government in curbing ghost fisheries is crucial.

Tracing the origin of olive ridley turtles entangled in ghost nets in the Maldives: A phylogeographic assessment of populations at risk

Abandoned, lost or discarded fishing gear, (ghost nets) represent a major threat to marine vertebrates. However, thorough assessments of their impact on threatened species are largely missing. In the Maldives, olive ridley sea turtles (Lepidochelys olivacea) are frequently caught in ghost nets however the archipelago does not support a significant nesting population. Our aim in this study was to determine the origin of olive ridleys entangled in ghost nets found in the Maldives and evaluate potential impacts on respective source populations.Based on a citizen science and conservation program, we recorded 132 olive ridley turtles entangled in ghost nets in just one year. Genetic analyses (mtDNA) of entangled individuals and of potential source populations revealed that most captured olive ridleys originated from Sri Lanka and eastern India. Oman could be excluded as a source population, even during the prevalence of the south west monsoon. Based on our results and already available published literature, we were able to estimate that the recorded ghost net entanglements accounted for a relatively small amount (0.48%) of the eastern Indian population. However, the entangled turtles accounted for a much larger percentage (41%) of the Sri Lankan populations. However, it should be noted that our estimates of population-level mortality are linked to substantial uncertainty due to the lack of reliable information on population dynamics. Consequently, any precautionary protection measures applied should be complemented with improved quantification of turtle recruitment and life-stage specific mortalities.

Minimum drift times infer trajectories of ghost nets found in the Maldives

This study explores methods to estimate minimum drift times of ghost nets found in the Maldives with the aim of identifying a putative origin. We highlight that percentage cover of biofouling organisms and capitulum length of Lepas anatifera are two methods that provide these estimates. Eight ghost nets were collected in the Maldives and estimated drift times ranged between 7.5 and 101 days. Additionally, Lagrangian simulations identified drift trajectories of 326 historical ghost nets records. Purse seine fisheries (associated with Korea, Mauritius, the Philippines, Spain, France and Seychelles) and gill nets from Sri Lanka were identified as 'high risk' fisheries with regard to likley origins of ghost nets drifting into the Maldives. These fisheries are active in areas where dense particle clusters occured (drift trajectories between 30 and 120 days). Interestingly, ghost nets drifting less than 30 days however, remained inside the exclusive economic zone of the Maldivian archipelago highlighting potential illegal, unreported and unregulated fishing activity is occuring in this area. This study therefore points to the urgent need for gear loss reporting to be undertaken, especially by purse seine and gill net fisheries in order to ascertain the source of this major threat to marine life. This should also be coupled with an improvment in the data focused on spatial distribution of the abandoned, lost or discarded fishing gear originating from both large- and small-scale fisheries.

Cetacean bycatch in Indian Ocean tuna gillnet fisheries

Pelagic gillnet (driftnet) fisheries account for some 34% of Indian Ocean tuna catches. We combined published results from 10 bycatch sampling programmes (1981−2016) in Australia, Sri Lanka, India and Pakistan to estimate bycatch rates for cetaceans across all Indian Ocean tuna gillnet fisheries. Estimated cetacean bycatch peaked at almost 100 000 ind. yr−1 during 2004−2006, but has declined by over 15% since then, despite an increase in tuna gillnet fishing effort. These fisheries caught an estimated cumulative total of 4.1 million small cetaceans between 1950 and 2018. These bycatch estimates take little or no account of cetaceans caught by gillnet but not landed, of delayed mortality or sub-lethal impacts on cetaceans (especially whales) that escape from gillnets, of mortality associated with ghost nets, of harpoon catches made from gillnetters, or of mortality from other tuna fisheries. Total cetacean mortality from Indian Ocean tuna fisheries may therefore be substantially higher than estimated here. Declining cetacean bycatch rates suggest that such levels of mortality are not sustainable. Indeed, mean small cetacean abundance may currently be 13% of pre-fishery levels. None of these estimates are precise, but they do demonstrate the likely order of magnitude of the issue. Countries with the largest current gillnet catches of tuna, and thus the ones likely to have the largest cetacean bycatch are (in order): Iran, Indonesia, India, Sri Lanka, Pakistan, Oman, Yemen, UAE and Tanzania. These 9 countries together may account for roughly 96% of all cetacean bycatch from tuna gillnet fisheries across the Indian Ocean.

Review of fish trap fisheries from tropical and subtropical reefs: Main features, threats and management solutions

Fish traps are extensively used in tropical and subtropical reef fisheries. Despite this, there is a significant lack of extensive and consecutive research concerning the basic aspects of trap fishing. We herein compile the available information from the main coral and rocky reef fish trap fisheries, and compared their main aspects (i.e., mesh size, CPUE, catch composition, ghost fishing, and management) to assess the dynamics of these fisheries and their environmental impact. The analysis revealed that most fish stocks showed declining trends, with only few species under heavy management being capable of withstanding high fishing pressure. In other fisheries, due to fishing down the web, miscellaneous reef fish comprised the bulk of the catch, while the proportion of high-value landed species was insignificant. Gear restrictions remain the most common management method in trap fisheries; however, even the minimum mesh size has not been ubiquitously enforced, while due to great variability of targeted fish species, use of a uniform mesh size is highly unlikely. Other management tools, such as, restrictions in effort, size, and species, temporal and spatial closures were also widely used, but effective only when well enforced and interconnected. Rates of trap loss widely differed as well as the reported rates of ghost fishing mortality. In most cases, incorporation of escape panels resulted in almost complete elimination of ghost fishing. However, further research is required concerning these issues.

Plastic world

Plastic world

NEW RECORD OF GIANT DEVIL RAY (CHONDRICHTHYES: MYLIOBATIDAE) FROM ORAN BAY (WESTERN MEDITERRANEAN SEA)

The present paper reports a new record of Giant devil ray Mobula mobular (Bonnaterre, 1788) from western Algerian waters that is encountered for the first time in that coast since its first description in 1901 and last observation in late 80’s. This elasmobranch is categorized as endangered on the IUCN Red List (Endangered A2d ver 3.1) and is likely to be the rarest of the nine species of Mobula genus. Occasionally it is captured in Mediterranean Sea by purse seines, bottom and pelagic trawls, pelagic nets, bottom longlines, drifters and harpoons. The specimen stranded in “la Madrague Beach” in Western Algerian coasts. Its disc length was measuring 108.96 cm and disc width was 226.02 cm. This Myliobatidae is rarely seen with daily landed fish at Oran fishery. Up to date no explicit reason can be given for the strand of M. mobular but ghost fishing and important maritime traffic stay the most plausible cause of this incident.

Effects of twine material on the marine debris and relative ghost fishing of portunid hoop (tangle) nets

Portunids are important to recreational fisheries in Australia and typically are harvested by baited gears. Most of these baited gears are considered environmentally benign, although small conical hoop (tangle) nets fished in southeastern Australia sometimes are damaged and lose twine, which becomes marine debris. Substituting conventional multifilament polyamide (PA) twine with alternative multi-monofilament and monofilament PA twines in hoop nets can dramatically reduce marine debris, but there remain unanswered questions concerning the relative fishing power of alternative twines among derelict hoop nets. This study addresses the shortfall in data by comparing the efficiencies and damage to replicate hoop nets made from the three twines and left to fish for short (one and two days), medium (three to five days) and long (ten and fourteen days) soaks. Irrespective of twine material or soak time, all hoop nets entangled the same numbers of giant mud crabs, Scylla serrata implying catch saturation within two days. Only four other animals were caught (all yellowfin bream, Acanthopagrus australis) and all died. At least some replicates of all hoop nets were damaged and lost twine, but this was greatest among the multifilament (up to a maximum of 9.3 m hoop-net deployment−1), followed by the multi-monofilament (up to 7.4 m hoop-net deployment−1) and monofilament hoop nets (1.4 m hoop-net deployment−1). Replacing the existing multifilament twine in hoop nets with monofilament when targeting S. serrata would maintain catches and minimise marine debris during conventional soaks, without increasing ghost fishing over the short term.

Drones detect illegal and derelict crab traps in a shallow water estuary

AbstractThe issues surrounding illegal, unregulated and unreported fishing, and that of abandoned, lost and discarded fishing gears, leading to ghost fishing, are intensifying. Estuarine crab trapping is likely subject to high levels of illegal and potential ghost fishing, because it also has good economic incentives regarding potential catch, low gear acquisition costs and accessible fishing grounds. To improve the efficiency and effectiveness of fisheries monitoring, control and surveillance operations, the efficacy of small consumer‐grade drones for sighting traps in an estuary in NSW, Australia, was tested. Twelve sets of two flights were undertaken at 20 and 30 m altitude over a 600‐m stretch of estuary for 5 days to quantify the detectability of submerged mesh traps of three different mesh colours. The drone was able to detect the majority of traps efficiently, with depth in relation to water clarity being the main factor affecting detection. In shallow water, detection rates were high for all mesh colours, but in the slightly deeper placements, orange traps were more readily detected. This study demonstrates that drones could be an efficient and reliable tool for rapidly assessing areas for illegal and derelict traps and can be supplemented into land or vessel‐based fisheries operations.

Detection of floating plastics from satellite and unmanned aerial systems (Plastic Litter Project 2018)

A rapidly rising amount of plastic litter on land and at sea is becoming a global wicked environmental problem. Here, we present an innovative exploratory application of unmanned aerial systems (UAS) and open-access satellite imagery in remote detection of floating plastics in natural seawater, through a dedicated aquatic environment experiment. We aimed to extract meaningful spectral measurements in near-real scenarios and to compare the geospatial information ranging from moderate to very high resolution. A set of three artificial floating plastic targets were setup for remote detection in the waters close to Tsamakia beach of Mytilene on Lesvos Island, Greece. These floating targets consisted of 100 m2 PET-1 1.5 L water bottles, LDPE plastic bags and nylon fishing ghost nets. Spectral properties of the controlled targets as well as surrounding seawater were investigated for Sentinel-2A satellite data. We demonstrate how UAS very high geospatial resolution images can be useful in improving geo-referencing of satellite images and how UAS can be used to assess the plastic percentage coverage of satellite images. We observed very weak to strong relationships between percentage pixel coverage and the spectral reflectance at p-value < 0.1 significance level. Effects of atmospheric correction algorithms was evaluated using Sen2Cor and ACOLITE, derive unbiased percentage differences were less than 65%. Our feasibility study demonstrated the importance of very high geo-spatial resolution UAS datasets in validating and enhancing the geo-spatial accuracy of satellite data for monitoring plastics in the aquatic environment. Monitoring and identifying plastics needs an integrated suite of sensors, we therefore present how available tools can be utilized to improve current efforts and contribute to advancing relevant future remote sensing technologies.

Breaking strength evaluation of biodegradable twines to reduce ghost fishing in the pot and trap fisheries of Chile

Passive fishing gears such as pots and traps can be constructed with a section of netting made from natural fibers. In the event the fishing gear is lost or abandoned, these fibers deteriorate which effectively disables the fishing gear and allows organisms which accidentally enter the gear, an opportunity to escape without harm. This study evaluated several twines manufactured from natural fibers for their suitability to reduce ghost fishing in pots and traps. Nine cotton and jute twines of different diameters and construction were selected from Valparaiso local market, Chile. The twines were submerged for 56 days in seawater under laboratory conditions. Measurements of breaking strength were performed every 14 days. A decrease in the mean breaking strength was observed after 56 days for all twines, ranging from 0.5 to 29.6% for jute twines and 12.8 to 71.7% for cotton twines. The time until total degradation was predicted to be 113-230 days for the twisted jute twines, 68-234 for the twisted cotton twines, and 108-205 for the braided cotton twines. Our results suggest that cotton twines are a more suitable and feasible option to be implemented. The need to perform trials of biodegradable devices under commercial fishing conditions is warranted.

Fishermen's perceptions of coastal fisheries management regulations: Key factors to rebuilding coastal fishery resources in Taiwan

Although Taiwan has taken conservation measures for coastal and offshore fishery resources in recent years, the effectiveness of resources rebuilding is unclear. Many initiatives, such as marine protected areas (MPAs), are frequently opposed by fishermen. This research reviewed management measures and interviewed 313 fishermen by purposive stratification and snowball sampling. Data were analyzed by fishery, age, and vessel size to address the attitudes and perceptions of fishermen toward twelve fisheries management measures. Descriptive statistics, as well as chi-squared tests and independent t-tests, were used for basic analysis and differences comparison between groups. The results showed that illegal fishing vessels from China (71%), overfishing (69.5%), and ghost fishing (64%) are considered as major threats to Taiwan marine resources. The measures from voyage data recorders, larval anchovy, precious coral, and shark management result in higher satisfaction because of strict monitoring. The satisfaction measures for three net-type measures, i.e., trawler area closure, torch-light limitation, and gillnet limitation, were low. Line-type and small-scale vessel fishermen are more concerned with “small mesh size” and “ghost fishing”. Net-type, large-scale vessels and young fishermen were concerned about “climate change” and “inappropriate measures”. In conclusion, the priorities are to (1) establish a comprehensive scientific research framework; (2) strengthen enforcement to ensure resources rebuilding, especially for large-scale net fisheries; (3) promote public awareness and build communication between stakeholders to obtain support; and (4) communicate among policymakers and fishermen to increase mutual understanding.

Comparison of fishing efficiency between biodegradable gillnets and conventional nylon gillnets

Gillnets made of a new biodegradable resin (polybutylene succinate co-adipate-co-terephthalate (PBSAT) were tested under commercial fishing conditions to compare their fishing performance with that of conventional nylon (PA) nets. The relative catch efficiency between the two gillnet types was evaluated over the entirewinter fishing season for cod (Gadus morhua) in northern Norway. The nylon gillnets caught 21% more fish (in numbers) than the biodegradable gillnets throughout the fishing season and generally showed better catch rates for most length classes, except for sizes between 82 and 90 cm. The difference in elasticity and breaking strength could explain the major difference in the size structure of fish caught by each type of gillnets, especially for larger fish. The number of times that the gillnets were deployed affected the relative catch efficiency of the gillnets with the biodegradable continuously loosing efficiency compared to the nylon. Although less catch efficient than nylon gillnets, biodegradable gillnets still show great potential for reduction of ghost fishing and plastic pollution at sea caused by this fishery.

Towards a Blue Humanity

Towards A Blue Humanity Ian Buchanan (bio) and Celina Jeffery (bio) Although the ocean covers seventy percent of the planet and provides more than half of the oxygen vital to all life on earth it figures comparatively little in global cultural production. Most of us tend to treat the ocean as that which must be traversed rather than explored for itself—we lay beside it at the beach, we cruise on its surface, or more usually fly several thousand feet above it, but we don't enter it (except perhaps for brief dives), and we certainly don't dwell in it. Yet ocean-going, particularly of cargo from China to the U.S., underpins globalization, so much so that the ocean has been described as the "missing context" of postmodernity, and from an environmental point of view, the ocean is a repository for plastic pollution, waste and effluence and is rapidly dying as global temperatures rise. There is a certain kind of politics of invisibility at work here—we do not comprehend complex eco-systems of oceans or the interdependence of the seas, earth and atmosphere. Much less, do we acknowledge the effects of the depletion, erasure and expulsion of biological life from much of the world's oceans. The ocean is, as Allan Sekula acknowledged, the "forgotten space" in which the twin fissures of oceanic degradation and social injustice are converging and ramifying (Sekula 2010). The "Anthropocene" ocean then is characterized by a particular kind of "slow violence" described by Rob Nixon, which is perhaps less visible and spectacular than a catastrophe like Deepwater Horizon oil spill might suggest, and yet more profoundly unjust and enduring in its long-term ramifications (2011, 21-22). The Intergovernmental Panel on Climate Change (IPCC) 2018 Special Report on Global Warming of 1.5% highlighted the urgency of action needed to address global warming of oceans, resulting in acidification, the bleaching of coral reefs, rising tides, and the melting of the circumpolar regions (IPCC report 2018). Added to this heady mix are the impacts of over-fishing, industrial fishing, and ghost nets which have already resulted in extinction patterns, interruption of local food chains, and extensive plastic waste. Additionally, pollution in the form of oil, fertilizers, nuclear waste, and noise have further contributed to oceanic toxification. The cascading effects of these factors and their impact upon the Earth's life support system have yet to be fully understood, but the appearance of dead zones—often caused by algal blooms particularly by phosphorous run off from farms—in numerous areas of the world's oceans are a shocking sign of impending [End Page 11] collapse. It is interesting to note that at this time such algal blooms have caused the citizens of Toledo, USA to attempt to give Lake Erie legal rights to protect the lake, called the Lake Erie Bills of Rights. What are the cultural discourses of this hitherto unimaginable erasure and expulsion of biological life from much of the world's oceans? This special issue reflects upon a growing body of work known as the "blue humanities" which is historicizing the ocean and making it part of contemporary consciousness in a way—we hope—that will enable environmental activism's bid to "save" the ocean. A cornerstone of this issue is how we understand blue humanities in the context of an ecological catastrophe that is rarely seen by the human eye. As Nixon argues in his book Slow Violence, without the attention of writer-activists—and we might add, artists, film-makers, poets, and photographers—the environmental issues we face could go unnoticed, misapprehended and unchecked (2011, 14-15). This special section of symplokē explores how we can leverage transdisciplinary inquiry and begins to say why we need not only a blue humanities but also a blue humanity—a sense in which we restore our sense of connectedness and in the words of Rachel Carson, "return to the sea," in part, through a consideration of the contributions of creative artists and thinkers (2014, 247). This issue gathers texts that use critical theory, philosophy and visual art and culture, to demarcate how ocean-based economies have resulted in transnational environmental trends with...

Untangling the origin of ghost gear within the Maldivian archipelago and its impact on olive ridley (Lepidochelys olivacea) populations

Untangling the origin of ghost gear within the Maldivian archipelago and its impact on olive ridley (Lepidochelys olivacea) populations

Building evidence around ghost gear: Global trends and analysis for sustainable solutions at scale

Abandoned, lost or discarded fishing gear (ALDFG) comprises a significant amount of global marine debris, with diverse impacts to marine environments, wildlife, and the fishing industry. Building evidence on ALDFG is critical to holistically understand the marine debris issue, and to inform the development of solutions that reduce amounts of ALDFG sources and recover existing gear. Substantial work has been and continues to be undertaken around the world to collect data on ALDFG, much of which remains unpublished. To provide a global picture of data on ALDFG, we organized a technical session that brought together seven ALDFG leaders to share their expertise in data collection, retrieval, and awareness-raising. This paper summarizes the technical session to highlight: 1) case studies that feature innovative approaches to ALDFG data collection and retrieval; 2) examples of opportunities to fill data gaps and improve our understanding of wildlife ingestion of and entanglement in ALDFG; and 3) awareness-raising through the development of a publicly accessible global ALDFG database.

Identification, recovery, and impact of ghost fishing gear in the Mullica River-Great Bay Estuary (New Jersey, USA): Stakeholder-driven restoration for smaller-scale systems

The impact of ghost fishing in large coastal ecosystems has generated considerable interest. In smaller, understudied systems with fewer stakeholders, derelict fishing gear (DFGs) may have impacts similar to these larger systems at the same relative scale. Four years of side scan sonar surveys in the Mullica River-Great Bay Estuary (New Jersey, USA) supported the recovery of 1776 DFGs off-season by commercial partners. Locations with high densities of recovered DFGs (>200 DFGs/km2) occupied intersections of recreational vessel traffic and commercial crabbing activity. Condition and depth-in-sediment of recovered DFGs was used to evaluate true bycatch (terrapins, whelks, blue crabs) versus species utilizing degraded gear as habitat (juvenile tautog, oyster toadfish). Critically, gear recovered in-season with low cost sonars (an additional 225 DFGs) prevented the accumulation of new DFGs which likely generate the highest percentages of bycatch. Removal of DFGs in this system led to significant ecological (reduced bycatch), economic (>$61,000 in direct pay, reused gear), and anticipated future benefits (increased harvest).

Ghost net removal in ancient Lake Ohrid: A pilot study

A pilot study on the occurrence of abandoned, lost or otherwise discarded fishing gear (ALDFG) was conducted in the Macedonian part of Lake Ohrid. Focussing on abandoned gill nets, different methods for detection and removal of these so-called ghost nets were tested and effects on biota assessed. As shown with the help of echo sounding, diving and creeping (i.e. towing of armed anchors and grapnels, respectively, over the ground), ghost nets were found to be widely present in this freshwater habitat. Altogether more than 12,000 m of nets were retrieved from water column and lake bottom. Free-floating nets were effectively detected using echo sounding, whereas masses of nets accumulated at underwater obstacles were easier to detect by diving. Creeping led to removal of less numerous but actively fishing ghost nets. Ghost nets contained fish at different stages of decomposition (in addition to birds and crustaceans) indicating that abandoned gear continues fishing over extended periods. Together, the results show that ghost nets are not only a marine problem but can significantly pollute freshwater lakes, too.

A review paper on the hazardous effect of plastic debris on marine biodiversity with some possible remedies

The consequences of plastic debris in the marine environment were reviewed, and possible solutions were presented. The extent of marine plastic debris-related problems surpasses many other marine problems, as plastics may be transported globally and no unaffected areas seem to exist. Many animal species are in risk, most commonly studied are the effects on marine mammals and seabirds. Marine plastic debris creates new concerns such as entanglement, ghost fishing, and impaction of digestive tracts in animals. It also increases the severity of already existing concerns such as transport, exposure and uptake of organic pollution, with reduced fitness and impaired reproduction and increased mortality rates as consequences. To alleviate the problems, reducing the extent of marine plastic pollution is critical. Possible methods were identified as collecting and incentivizing recycling of marine plastic debris; redirecting production from petroleum plastics to biodegradable varieties; increase public awareness to reduce marine littering; stricter enforcement of current legislation as well as implementation of stricter legislation and harsher penalties for breaking it.Asian J. Med. Biol. Res. September 2018, 4(3): 233-241