|
|
|
|
|
| Blanchard, Julia L.; Coll, Marta; Trenkel, Verena; Vergnon, Remi; Yemane, Dawit; Jouffre, Didier; Link, Jason S.; Shin, Yunne-jai. |
| Time-series of ecological and exploitation indicators collected from 19 ecosystems were analysed to investigate whether there have been temporal trends in the status of fish communities. Using linear and non-linear statistical methods, trends are reported for six indicators (mean length of fish in the community, mean lifespan, proportion of predatory fish, total biomass of surveyed species, mean trophic level of landings, and inverse fishing pressure), and the redundancy of these indicators across ecosystems is evaluated. The expected direction of change for an ecosystem that is increasingly impacted by fishing is a decline in all indicators. A mixture of negative and positive directions of change is recorded, both within and among all ecosystems... |
| Tipo: Text |
Palavras-chave: Community; Ecological indicators; Ecosystem-based fisheries management; Ecosystem effects of fishing; Natural resource management. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00002/11373/8166.pdf |
| |
|
|
| Kreiner, Anja; Yemane, Dawit; Stenevik, Erling K.; Moroff, Nadine E.. |
| Most reports on the distribution of spawning areas of sardine (Sardinops sagax) in the northern Benguela originate from the 1970s and 1980s. The northern Benguela system was in a high upwelling regime during those decades. Since the early 1990s upwelling favourable winds have decreased and a trend of increasing sea surface temperature (SST) has been observed. Changes in the structure of sardine stock in the northern Benguela have been observed and it has been suggested that a reduced biomass and changes in stock structure has led to decreased spawning in the favourable southern locations, thus preventing a recovery of the sardine stock. The present paper on the contrary shows that there has been a shift in spawning location from the less favourable... |
| Tipo: Journal Contribution |
Palavras-chave: Coastal upwelling; Upwelling system; Temperature; Spawning; Seasonal changes. |
| Ano: 2011 |
URL: http://hdl.handle.net/1834/4625 |
| |
|
|
|
