Marine vertebrate strandings data can provide insights into the long-term dynamics of cetacean populations, and the threats they face. We investigate whether the spatio-temporal patterns of cetacean strandings around Cornwall, SW Britain, have changed in the past century. Analysis of strandings from 1911 to 2006 (n = 2,257) show that, since the mid-1970s, the relative frequency of strandings of common dolphins (Delphinus delphis), harbour porpoises (Phocoena phocoena) and pilot whales (Globicephala melas) has increased signiWcantly. Seasonal peaks in strandings frequencies are apparent, between December and March for harbour porpoises and common dolphins, and between November and January for pilot whales. There were signiWcant positive trends in the number of common dolphin and harbour porpoise strandings, as a proportion of total strandings, over time. Strandings of common dolphins, porpoises and all other species occur more frequently on the south coast of Cornwall. A total of 415 cetaceans were subject to full veterinary necropsy to determine cause of death, between 1990 and 2006, and 253 (61%) of these individuals were determined to have died due to bycatch in Wshing gear. Analyses of industrialised Wshing pressure in UK waters show the seas around Cornwall to be one of the Electronic supplementary material The online version of this article (1 C most heavily Wshed areas of the UK. We suggest a number of factors that could be responsible for the recent increases in cetacean strandings in southwest UK waters in recent years, including survey eVort, as well as abundance and range shifts that are potentially linked with climate change. Although detectable levels of bycatch rate have not increased over time, Wsheries interactions are in signiWcant part responsible for mortality patterns and are worthy of more detailed investigation.

Extinctions on land are often inferred from sparse sightings over time, but this technique is ill-suited for wide-ranging species. We develop a space-for-time approach to track the spatial contraction and drivers of decline of sawfishes. These iconic and endangered shark-like rays were once found in warm, coastal waters of 90 nations and are now presumed extinct in more than half (n = 46). Using dynamic geography theory, we predict that sawfishes are gone from at least nine additional nations. Overfishing and habitat loss have reduced spatial occupancy, leading to local extinctions in 55 of the 90 nations, which equates to 58.7% of their historical distribution. Retention bans and habitat protections are urgently necessary to secure a future for sawfishes and similar species.

Sawfishes have declined dramatically in West Africa and may be extinct throughout much of their historical range. Guinea‐Bissau is considered to be one of the last remaining places in West Africa where sawfish persist. Fishers’ ecological knowledge (FEK) can provide valuable baseline data, which can be used to direct scientific studies, in situations where information is scarce or lacking and can also provide insight into local attitudes towards species of interest. Interview surveys were used to collect FEK data on the past and current range of sawfishes within Guinea‐Bissau waters, perceived causes of the decline amongst fishermen, and the cultural importance of this species to Bissau‐Guineans. Data were collected from 274 respondents, of whom 85% could identify a sawfish from an image. The majority of respondents reported to have last seen a sawfish in the 1980s, although this varied considerably by region, and 30% of respondents in the south had seen or captured sawfishes in the past decade up to and including 2012. Overfishing or excessive fishing pressure was most frequently cited as a perceived cause for the decline in sawfish, followed by shark finning and overseas fishermen. The sawfish is primarily of cultural importance in the Bijagos Islands, where it is central to many traditional ceremonies. This information provides valuable insight into the cultural importance of sawfish to Bissau‐Guineans and their concerns in relation to the sustainability of their local fishery resources. Information on recent catches will be useful for directing future work to locate and protect remaining sawfish in Guinea‐Bissau. Copyright © 2013 John Wiley & Sons, Ltd.

Humpback whales found off west South Africa (WSA) are known to display an atypical migration that may include temporary residency and feeding during spring and summer. At a regional scale there is uncertainty about how these whales relate to the greater West African Breeding Stock B as a whole, with evidence both for and against its division into two sub-stocks. A database containing sighting information of humpback whales intercepted by were between different calendar years. The most resightings for one individual was 11 times, seen in six different years, while the longest interval between first and last sightings was about 18 years. A resighting rate of 15.6% of whales at intervals of a year or more indicates long-term fidelity to the region. Shorter intervals of 1 -6 months between sequential sightings in the same year may suggest temporary residency. The TF image collection from WSA was compared to TF collections from four other regions, namely Gabon, Cabinda (Angola), Namibia and the Antarctic Humpback Whale Catalogue (AHWC). Three matches were detected were between WSA (in late spring or summer) and Gabon (in winter), confirming direct movement between these regions. The capture-recapture data of four different identification features (TF, RDF, LDF and MS) from six successive subsets of data from periods with the highest collection effort (2001 -2007), were used to calculate the number of whales that utilise the region, using both closed and open-population models. Since dorsal fins have never been used to estimate abundance for humpback whales, the different identification features were evaluated for potential biases. This revealed 9 -14% incidence of missed matches (false negatives) when using dorsal fins that will result in an overestimate, while variation in individual fluke-up behaviour may lower estimates due to heterogeneity of individual capture probability, by as much as 57-69%. Taking into consideration the small dataset and low number of recaptures, the most consistent and precise results were obtained from a fully time-dependent version of the Jolly-Seber open-population model, with annual survival fixed at 0.96, using the MS dataset. This suggests that the WSA feeding assemblage during the months of spring and summer of the study period numbered about 500.The relationship of these whales to those (perhaps strictly migratory) that may occur here in other seasons of the year, and their links to possible migratory routes and other feeding or breeding areas remain uncertain.