ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Publication Date: 2019-12-20
    Description: The Law of the Sea and regional and national laws and agreements require exploited populations or stocks to be managed so that they can produce maximum sustainable yields. However, exploitation level and stock status are unknown for most stocks because the data required for full stock assessments are missing. This study presents a new method [abundance maximum sustainable yields (AMSY)] that estimates relative population size when no catch data are available using time series of catch-per-unit-effort or other relative abundance indices as the main input. AMSY predictions for relative stock size were not significantly different from the “true†values when compared with simulated data. Also, they were not significantly different from relative stock size estimated by data-rich models in 88% of the comparisons within 140 real stocks. Application of AMSY to 38 data-poor stocks showed the suitability of the method and led to the first assessments for 23 species. Given the lack of catch data as input, AMSY estimates of exploitation come with wide margins of uncertainty, which may not be suitable for management. However, AMSY seems to be well suited for estimating productivity as well as relative stock size and may, therefore, aid in the management of data-poor stocks.
    Print ISSN: 1054-3139
    Electronic ISSN: 1095-9289
    Topics: Biology , Geosciences , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 2021-08-25
    Description: In the last decades, several targets for marine conservation were set to counter the effects of increasing fishing pressure, e.g., protecting 10% of the sea by 2020, and establishing large-scale marine protected areas (LSMPAs). Using the ‘reconstructed’ catch data for 1950 to 2018 made available by the Sea Around Us initiative, we show that the declaration of an exclusive economic zone (EEZ) in 1983 by the U.S.A. and its protection by the U.S. Coast Guard had a much bigger impact on catches around the Northwestern Hawaiian Islands than the subsequent creation of a LSMPA. This is similar to Pitcairn Islands, a UK territory. Trends differed sharply in the Galapagos and New Caledonia, where neither their EEZ declaration nor the LSMPA (by Ecuador in 1988 and by France in 2014) stopped local fisheries from continuous expansion. Our results also demonstrate that in the studied multizone LSMPAs continued local fishing induces a ‘fishing down’ effect wherein the mean trophic level (TL) declined, especially in the Galapagos, by 0.1 TL per decade. Stakeholders’ responses to a short questionnaire and satellite imagery lent support to these results in that they documented substantial fishing operations and ‘fishing the line’ within and around multizone LSMPAs. In the case of EEZs around less populated or unpopulated islands, banning foreign fishing may reduce catch much more than a subsequent LSMPA declaration. This confirms that EEZs are a tool for coastal countries to protect their marine biodiversity and that allowing fishing in an MPA, while politically convenient, may result in ‘paper parks’ within which fishing can cause the same deleterious effects as in wholly unprotected areas.
    Electronic ISSN: 2071-1050
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...