Over the past two decades, sharks have been increasingly recognized among the world's most threatened wildlife and hence have received heightened scientific and regulatory scrutiny. Yet, the effect of protective regulations on shark fishing mortality has not been evaluated at a global scale. Here we estimate that total fishing mortality increased from at least 76 to 80 million sharks between 2012 and 2019, ~25 million of which were threatened species.
View Article and Find Full Text PDFScientific bottom-trawl surveys are ecological observation programs conducted along continental shelves and slopes of seas and oceans that sample marine communities associated with the seafloor. These surveys report taxa occurrence, abundance and/or weight in space and time, and contribute to fisheries management as well as population and biodiversity research. Bottom-trawl surveys are conducted all over the world and represent a unique opportunity to understand ocean biogeography, macroecology, and global change.
View Article and Find Full Text PDFMarine heatwaves have been linked to negative ecological effects in recent decades. If marine heatwaves regularly induce community reorganization and biomass collapses in fishes, the consequences could be catastrophic for ecosystems, fisheries and human communities. However, the extent to which marine heatwaves have negative impacts on fish biomass or community composition, or even whether their effects can be distinguished from natural and sampling variability, remains unclear.
View Article and Find Full Text PDFSharks and rays are key functional components of coral reef ecosystems, yet many populations of a few species exhibit signs of depletion and local extinctions. The question is whether these declines forewarn of a global extinction crisis. We use IUCN Red List to quantify the status, trajectory, and threats to all coral reef sharks and rays worldwide.
View Article and Find Full Text PDFNPJ Ocean Sustain
August 2023
Although the Paris Agreement establishes targets to limit global warming-including carbon market mechanisms-little research has been done on developing operational tools to achieve them. To cover this gap, we use CO permit markets towards a market-based solutions (MBS) scheme to implement blue carbon climate targets for global fisheries. The scheme creates a scarcity value for the right to not sequester blue carbon, generating an asset of carbon sequestration allowances based on historical landings, which are considered initial allowances.
View Article and Find Full Text PDFFishing provides the world with an important component of its food supply, but it also negatively impacts the biodiversity of marine and freshwater ecosystems, especially when industrial fishing is involved. To mitigate these impacts, civil society needs access to fisheries data (i.e.
View Article and Find Full Text PDFPhilos Trans R Soc Lond B Biol Sci
December 2019
Ecological baselines-reference states of species' distributions and abundances-are key to the scientific arguments underpinning many conservation and management interventions, as well as to the public support to such interventions. Yet societal as well as scientific perceptions of these baselines are often based on ecosystems that have been deeply transformed by human actions. Despite increased awareness about the pervasiveness and implications of this shifting baseline syndrome, ongoing global assessments of the state of biodiversity do not take into account the long-term, cumulative, anthropogenic impacts on biodiversity.
View Article and Find Full Text PDFWhile the ecological impacts of fishing the waters beyond national jurisdiction (the "high seas") have been widely studied, the economic rationale is more difficult to ascertain because of scarce data on the costs and revenues of the fleets that fish there. Newly compiled satellite data and machine learning now allow us to track individual fishing vessels on the high seas in near real time. These technological advances help us quantify high-seas fishing effort, costs, and benefits, and assess whether, where, and when high-seas fishing makes economic sense.
View Article and Find Full Text PDFClimate change-reflected in significant environmental changes such as warming, sea level rise, shifts in salinity, oxygen and other ocean conditions-is expected to impact marine organisms and associated fisheries. This study provides an assessment of the potential impacts on, and the vulnerability of, marine biodiversity and fisheries catches in the Arabian Gulf under climate change. To this end, using three separate niche modelling approaches under a 'business-as-usual' climate change scenario, we projected the future habitat suitability of the Arabian Gulf (also known as the Persian Gulf) for 55 expert-identified priority species, including charismatic and non-fish species.
View Article and Find Full Text PDFThe development of fisheries in the oceans, and other human drivers such as climate warming, have led to changes in species abundance, assemblages, trophic interactions, and ultimately in the functioning of marine food webs. Here, using a trophodynamic approach and global databases of catches and life history traits of marine species, we tested the hypothesis that anthropogenic ecological impacts may have led to changes in the global parameters defining the transfers of biomass within the food web. First, we developed two indicators to assess such changes: the Time Cumulated Indicator (TCI) measuring the residence time of biomass within the food web, and the Efficiency Cumulated Indicator (ECI) quantifying the fraction of secondary production reaching the top of the trophic chain.
View Article and Find Full Text PDFHistorical data are essential in fisheries management and conservation, especially for species that suffered significant population declines prior to ecological data collection. Within the field of historical marine ecology, studies have relied on anecdotal evidence, such as written accounts by explorers and interviews of different generations of resource users, to demonstrate the former abundance of certain species and the extent of their ranges. Yet, do we all agree on how these anecdotes are interpreted? This study examines the way that different people interpret anecdotes extracted from historical narratives.
View Article and Find Full Text PDFHist Philos Life Sci
May 2008
This work presents a review of the status of marine resources of the Raja Ampat Archipelago, Papua Province, Indonesia, based on narratives of early European expeditions in various museums and libraries in Europe, Canada, and local archives in Papua. More than 500 pertinent documents on the study area were identified and located in various European museums and at the University of British Columbia library. About half of these were scanned (25,000 pages), which yielded the equivalent of 900 pages of text (or 4% of the total number of pages scanned) with observations on abundance and impact of the human population on the marine ecosystem within 2 degrees North and 2 degrees South between 127 degrees and 132 degrees East.
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