Predicting the distribution and abundance of abandoned, lost or discarded fishing gear (ALDFG) in the deep sea of the Azores (North Atlantic)

Assessing marine litter on the VMEs of el Seco de los Olivos (W Mediterranean Sea)

The Mediterranean Sea, as a semi-enclosed and highly-populated basin, is one of the world's largest hotspots for marine litter (ML). In the present study, we quantified the abundance, composition and impacts of ML on Vulnerable Marine Ecosystems of the Chella Bank (Alboran Sea), which is part of the Sur de Almería - El Seco de los Olivos Site of Community Importance (SCI) of the European Marine Natura 2000 network (ESZZ16003). A total of fifty-five ROV video transects (2010-2012) were analyzed, covering an approximate linear distance of 67.52 km across a depth range of 76-700 m. ML observations were used to generate predictive maps of litter distribution using Generalized Additive Models, reveling frequent 'hotspot' areas where ML accumulates. Abandoned, Lost or Discarded Fishing Gears (ALDFGs) were the main source of marine debris, especially longlines which accounted to 80 % of litter items. Seabed complexity and fishing effort explained the distribution of ALDFGs, with maximum items density (7.02 items m-2) observed on the crests of the ridges, known to host vulnerable deep-sea reefs, animal forests and sponge grounds. As a result, entanglement was the main source of impact on benthic fauna, with multiple colonies of anthozoans significantly ensnared within longlines and trammel nets. The results of the present study provide adds more evidence that the Mediterranean Sea is one of the most polluted basins in the world, and deepens into the impacts of Marine Litter on the sensitive habitats of El Seco de los Olivos which may contribute to the development of a management plan supporting its designation as an EU Special Area of Conservation (SAC).

Is there something fishy about that litter? A UK case study on abandoned, lost or otherwise discarded fishing gear

Fisheries related litter including Abandoned, Lost or otherwise Discarded Fishing Gear (ALDFG) is recognised as one of the most harmful types of marine plastic litter. It makes up a substantial proportion of litter from sea-based sources and poses significant threat to marine ecosystems, and livelihoods. This paper provides the first comprehensive description of fisheries related litter on the seafloor around the UK, detailing sources and item descriptions. Existing litter data were reanalysed by examining photographs and descriptions of litter items taken from surveys in the North Sea (2016-2020) and the Celtic Seas (2018-2022). More than half of all litter items (by count) were identified as fisheries related litter (51 % for North Sea and 53 % for Celtic Seas), with the majority specifically identified as ALDFG (33 % for the North Sea and 36 % for Celtic Seas), mostly originating from trawl fisheries (96 % for North Sea and 89 % for Celtic Seas). The top items (by count) identified were dolly rope, trawl net, rope and net cuttings, and hotspots of ALDFG were identified off the Yorkshire coast, in the North Sea and off the South West of the UK, in the Celtic Seas. This shows that fisheries significantly contribute to marine litter around the UK and demonstrates that existing monitoring data can contribute towards our understanding of the topic. The findings of this study can support UK and regional efforts to reduce fisheries related litter and guide targeted prevention, mitigation and remediation measures to address plastic pollution.

An index to differentiate megafauna entangled in operational fishing gears from abandoned, lost, or otherwise discarded fishing gears

Classifying entanglements of marine megafauna in certain anthropogenic items is challenging because many are found in fishing-related items, with the cause being either operational fishing gear (OFG) or abandoned, lost, or otherwise discarded fishing gear (ALDFG). The distinction between OFG and ALDFG is essential as each source requires different mitigation and remediation strategies. To reduce the uncertainty in sorting between these two distinct threats, we developed the Entanglement Source Assessment (ENSA) index. This index integrates a series of criteria related to the entangling item and the affected organism. It assess the likelihood that an entanglement was caused by an OFG or by an ALDFG using a Multi-Criteria Decision Analysis approach. The index was tested on 35 entanglement events involving various taxa, using video footage and photographs recorded in the Azores Archipelago (NE Atlantic). Overall, 57 % of the entanglements were classified as likely caused by ALDFG (ENSA scoring >60), indicating they resulted from marine debris. In comparison, 23 % were classified as likely from interactions with OFG (ENSA scoring ≤40). The remaining events were ambiguous and could not be confidently assigned to either source. ENSA is a valuable tool that integrates expert knowledge, transparently providing a clear view of the steps and reasoning behind the classification process. It will promote standardization when reporting the source (OFG vs. ALDFG), which is essential for implementing adequate policy measures to address the entanglement of marine megafauna in fishing-related items at national and global scales.

Density and distribution patterns of seafloor macrolitter in the eastern Red Sea

The constant production of plastic and incessant growth of waste pollution continues to alter the marine environment from the coasts and surface waters to the deep sea. The quantification and investigation of macrolitter on the vast seabed of the ocean are challenging tasks that must be undertaken to elucidate the impact of anthropogenic activity on the marine environment and facilitate subsequent implementation of legally binding waste management regulations. In this study, we analyzed >60,000 images collected during 84 dives surveying 62.1 km of seabed in the eastern Red Sea to quantify the abundance and density of seafloor macrolitter. The surveyed depth of the seabed varied between 35 and 2415 m, and litter was observed at depths ranging from 93 to 2415 m. The litter density varied between 0 and 73,798 items km-2, with the mean (± SE) and median densities of 4069 ± 1188 and 1371 items km-2, respectively. Plastic was the main litter category, comprising 46 % of all litter. The density of litter was higher at deeper depths (>1400 m) and increased significantly at distances farther from the shore. The results of this study suggest that maritime traffic and the possible direct litter discharge from vessels are the main anthropogenic sources of seafloor litter in the eastern Red Sea. Thus, we emphasize the urgency of conservation efforts and strict waste regulations to preserve the marine ecosystem of the Red Sea.

Incorporation of abandoned and lost fishing gear into the structure of Dendrophyllia ramea in the Atlantic coast of Portugal

Plastic pollution poses global and societal concerns, especially from discarded fishing gear, threatening seabed environments like coral reefs. This study examines the incorporation of lost and/or abandoned fishing gear - specifically synthetic lines, and filaments - into the structure of orange tree coral, Dendrophyllia ramea along the coast of Portugal, in the North-East Atlantic Ocean. The specimens were inadvertently captured by local fishers (Sines and Cascais), with 6 % showing filaments inside their structure, raising questions about their potential impact on coral health. We discuss the implications of understanding the interactions between plastics, fishing gear, and corals, which is important for developing conservation strategies. We address the need for improved of measures aimed at reducing the impact of fishing gear on corals, emphasizing the importance of endorsing biodegradable fishing materials and supporting lost gear retrieval initiatives. Furthermore, we emphasize the urgent need to communicate these issues to both fishers and stakeholders.