Combining fishery-independent and -dependent catch observations in a single index of abundance by allowing for spatially varying catchability 

John Best, Jim Thorson, Rick Methot, Andre Punt

October 29th, 2019 9:00 AM (PST): FSH 203

For fisheries where both fishery-independent and -dependent catch observations are available, spatiotemporally standardized indices of abundance currently use only the fishery-independent data because it is difficult to reliably standardize fishery-dependent observations. There may be an order of magnitude more fishery-dependent observations than fishery-independent observations, representing a currently unused source of information. Integrating these two types of data into a single index of abundance may increase precision, but the fishery-dependent observations would need to be standardized carefully to avoid unacceptable levels of additional bias. One approach to standardizing fishery-dependent observations in a spatiotemporal standardization model would include spatial and/or spatiotemporal random effects on catchability. A model that allows this will be presented along with preliminary simulation study results.

Brazilian fishery stock assessment and management: current status and challenges

Flávia Lucena Frédou – Universidade Federal Rural de Pernambuco (Recife – Brazil)

November 5th, 2019 9:00 AM (PST): FSH 203

There is a large diversity of species and fishing gear/methods in Brazilian marine waters, given the long coast (more than 7000 km long), with different environments and a multispecies and multifleet fishery. Most of the industrial fishing fleet is concentrated in Southern Brazil, while most of the small-scale fisheries (SSF) is concentrated in the north and northeast regions (Bertrand et al., 2018), where the activity is extremely important in terms of food security and employment (over 90% of jobs in the fishery sector concentrates). Based on a multi-year Brazilian research Program REVIZEE (Avaliação do Potencial Sustentável da Zona Econômica Exclusiva do Brasil), created by the Brazilian Government in compliance with the United Nations Convention of the Law of the Sea, by the early 2000s, Brazilian fisheries far exceeded sustainable target levels in the main portion and the majority of stocks were either fully (23%) or over-exploited (33%) (MMA, 2006). Moreover, Brazilian Fisheries Statistics have not been reported since 2007, when the existing system was gradually dismantled and not replaced. Hence, the assessment and the management of the Brazilian fishery resources have been a great challenge for scientists and government.  After the Program REVIZEE ended, stocks have never been re-assessed at a national level. However, specific initiatives were established in order to assess the sustainability and conservation of some fishery resources. More recently (2010 – 2014), Brazilian aquatic resources have  been evaluated according to the IUCN Red List categories at a regional scale, in a process  leaded by the ICMBio (Instituto Chico Mendes de Conservação da Biodiversidade, Ministério do Meio Ambiente, Brazil). The red list, published in 2014 (Portaria 445), enumerated 475 aquatic species as threatened. Moreover, research initiatives funded by the Fishery and Aquaculture Secretary (Ministry of Agriculture) and CNPq (National Research Council) are in place in order to evaluate the main fishery resources of the country. This talk will review the initiatives of the Brazilian Government in assessing its stocks and the current challenge given the diversity and the data-limited nature of the national fisheries.