Adapting the Marine Stewardship Council risk-based framework to estimate impacts on seabirds, marine mammals, marine turtles and sea snakes

This is the final version. Available from Elsevier via the DOI in this record. Information available on impacts of fisheries on target or bycatch species varies greatly, requiring development of risk assessment tools to determine potentially unacceptable levels. Seabirds, marine mammals, marine turtles and sea snakes are particularly vulnerable given their extreme life histories, and data are often lacking on their populations or bycatch rates with which to quantify fisheries impacts. The Marine Stewardship Council (MSC) use a semi-quantitative Productivity Susceptibility Analysis (PSA) that is applicable to all species, target and non-target, to calculate risk of impact and to provide a score for relevant Performance Indicators for fisheries undertaking certification. The most recent MSC Fisheries Standard Review provided an opportunity to test the appropriateness of using this tool and whether it was sufficiently precautionary for seabirds, marine mammals and reptiles . The existing PSA was tested on a range of species and fisheries and reviewed in relation to literature on these species groups. New taxa-specific PSAs were produced and then reviewed by taxa-specific experts and other relevant stakeholders (e.g., assessors, fisheries managers, non-governmental conservation organizations). The conclusions of the Fishery Standard Review process were that the new taxa-specific PSAs were more appropriate than the existing PSA for assessing fisheries risk for seabirds, marine mammals and reptiles, and that, as intended, they resulted in precautionary outcomes. The taxa-specific PSAs provide useful tools for true data-deficient fisheries to assess relative risk of impact. Where some data are available, the MSC could consider developing or adapting other approaches to support robust and relevant risk assessments.Marine Stewardship Counci

Updating requirements for Endangered, Threatened and Protected species MSC Fisheries Standard v3.0 to operationalise best practices

This is the final version. Available from Elsevier via the DOI in this record. Bycatch in fisheries is a key threat to non-target marine species, particularly for those species that have life histories with low productivity or poor conservation status. In this paper, the requirements of the new Marine Stewardship Council (MSC) Fisheries Standard (hereafter “the Standard”) are summarised relevant to Endangered, Threatened and Protected (ETP) species. This covers both how species are designated as ETP, and how performance of management is assessed with respect to ETP species, when scoring fisheries against the Standard. The process used to select these requirements is described, including a review of the requirements for earlier versions of the Standard and the scoring of these requirements in assessment reports for a selection of fisheries that have achieved MSC certification. The review identified a lack of consistency in the implementation of scoring guidelines, which was in part due to a lack of clarity in the requirements of the Standard. The revised Standard has been designed to achieve more consistent implementation of the requirements with respect to management of impacts on ETP species, and to align the requirements more closely with global best practice. The requirements may be used as a template for fisheries managers seeking to prioritise bycatch species for improved management and setting more specific and measurable objectives in relation to population status and minimising mortalities.Marine Stewardship Counci

Population growth of Mexican free-tailed bats (Tadarida brasiliensis mexicana) predates human agricultural activity

Background Human activities, such as agriculture, hunting, and habitat modification, exert a significant effect on native species. Although many species have suffered population declines, increased population fragmentation, or even extinction in connection with these human impacts, others seem to have benefitted from human modification of their habitat. Here we examine whether population growth in an insectivorous bat (Tadarida brasiliensis mexicana) can be attributed to the widespread expansion of agriculture in North America following European settlement. Colonies of T. b. mexicana are extremely large (~106 individuals) and, in the modern era, major agricultural insect pests form an important component of their food resource. It is thus hypothesized that the growth of these insectivorous bat populations was coupled to the expansion of agricultural land use in North America over the last few centuries. Results We sequenced one haploid and one autosomal locus to determine the rate and time of onset of population growth in T. b. mexicana. Using an approximate Maximum Likelihood method, we have determined that T. b. mexicana populations began to grow ~220 kya from a relatively small ancestral effective population size before reaching the large effective population size observed today. Conclusions Our analyses reject the hypothesis that T. b. mexicana populations grew in connection with the expansion of human agriculture in North America, and instead suggest that this growth commenced long before the arrival of humans. As T. brasiliensis is a subtropical species, we hypothesize that the observed signals of population growth may instead reflect range expansions of ancestral bat populations from southern glacial refugia during the tail end of the Pleistocene

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Marine mammal conservation: over the horizon

Marine mammals can play important ecological roles in aquatic ecosystems, and their presence can be key to community structure and function. Consequently, marine mammals are often considered indicators of ecosystem health and flagship species. Yet, historical population declines caused by exploitation, and additional current threats, such as climate change, fisheries bycatch, pollution and maritime development, continue to impact many marine mammal species, and at least 25% are classified as threatened (Critically Endangered, Endangered or Vulnerable) on the IUCN Red List. Conversely, some species have experienced population increases/recoveries in recent decades, reflecting management interventions, and are heralded as conservation successes. To continue these successes and reverse the downward trajectories of at-risk species, it is necessary to evaluate the threats faced by marine mammals and the conservation mechanisms available to address them. Additionally, there is a need to identify evidence-based priorities of both research and conservation needs across a range of settings and taxa. To that effect we: (1) outline the key threats to marine mammals and their impacts, identify the associated knowledge gaps and recommend actions needed; (2) discuss the merits and downfalls of established and emerging conservation mechanisms; (3) outline the application of research and monitoring techniques; and (4) highlight particular taxa/populations that are in urgent need of focus