Coral reefs are the most biologically diverse of shallow water marine ecosystems but are being degraded worldwide by human activities and climate warming. Analyses of the geographic ranges of 3235 species of reef fish, corals, snails, and lobsters revealed that between 7.2% and 53.6% of each taxon have highly restricted ranges, rendering them vulnerable to extinction. Restricted-range species are clustered into centers of endemism, like those described for terrestrial taxa. The 10 richest centers of endemism cover 15.8% of the world's coral reefs (0.012% of the oceans) but include between 44.8 and 54.2% of the restricted-range species. Many occur in regions where reefs are being severely affected by people, potentially leading to numerous extinctions. Threatened centers of endemism are major biodiversity hotspots, and conservation efforts targeted toward them could help avert the loss of tropical reef biodiversity.

Since the 1970s the role of fishery bycatch as a factor reducing, or limiting the recovery of, marine mammal populations has been increasingly recognized. The proceedings of a 1990 International Whaling Commission symposium and workshop summarized fishery and bycatch data by region, fishery, and species, and estimated the significance of the 'impacts' of bycatch in passive gear on all cetacean species and subspecies or geographically defined populations. A global review of pinniped bycatch in 1991 concluded that incidental mortality in passive gear had contributed to declines of several species and populations. Here we update the information on cetacean gillnet bycatch, assess bycatch data on marine mammals other than cetaceans (i.e. pinnipeds, sirenians, and 2 otter species), determine where important data gaps exist, and identify species and populations known or likely to be at high risk from bycatch in gillnets. We found that at least 75% of odontocete species, 64% of mysticetes, 66% of pinnipeds, and all sirenians and marine mustelids have been recorded as gillnet bycatch over the past 20-plus years. Cetacean bycatch information in some areas has improved, facilitating our ability to identify species and populations at high risk, although major gaps remain. Understanding of the scale of pinniped and sirenian bycatch has also improved, but this bycatch remains poorly documented, especially at the population level. This study reveals how little is known about marine mammal bycatch in gillnets in much of the world. Even as other significant threats to marine mammals have become better documented and understood, bycatch remains a critical issue demanding urgent attention if there is to be any hope of preventing further losses of marine mammal diversity and abundance, and of protecting, or restoring, ecological health.

Demersal and pelagic longline fisheries involve frequent and geographically widespread interactions with many individuals, populations, and species of marine mammals. Animals sometimes suffer mortality and serious injury following these interactions, attracted mainly to longlines as a source of food. This depredating behaviour can have serious consequences for fishermen, especially when they lose valuable catch and face other associated operational and regulatory challenges. Using input from a group of international experts in the science, fishing industry, and government sectors, we produced a list of methods for mitigating depredation and bycatch of marine mammals in longline fisheries, collectively assessed their potential as a solution, and determined priorities for further research. The intention of this review is to help synthesize our current understanding about potential solutions, to provide an introduction to the articles that appear in this themed set of the ICES Journal of Marine Science, and to help fishermen, fisheries managers, and research scientists advance solutions to this global problem.

(SD 8.29), which is 26% lower than strength at manufacture (range 2.89-53.38 kN, mean = 15.70 kN [9.89] (DS 8.29), que es 26% más baja que la fuerza en manufactura (rango 2.89-53.38 kN, media = 15.70 kN [9.89] (Balaenoptera acuturostrata) (19.30, 17.13, y 10.47 media de kN, respectivamente