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Stanley, Falkland Islands

Ashford J.R.,Old Dominion University | Fach B.A.,Middle East Technical University | Arkhipkin A.I.,Falkland Islands Government | Jones C.M.,Old Dominion University
Fisheries Research | Year: 2012

We used a wind-driven global circulation model to build spatially explicit predictions from rival hypotheses concerning advective supply of Patagonian toothfish (Dissostichus eleginoides) to a trawl fishery around the Falkland Islands, and tested the predictions using chemistry recorded in the otoliths of fish caught in the fishery. Model simulations indicated transport pathways from spawning aggregations off southern Chile to both the north and south of the fishing area. In contrast, simulated particles released from spawning aggregations around Burdwood Bank were transported to the south of the fishing area but not to the north, becoming fully entrained in the Subantarctic Front instead. Spatial heterogeneity in the chemistry laid down in the otolith nuclei during early life discounted the hypothesis of a single population with a spawning area on Burdwood Bank, and indicated that fish assemblages are structured by large-scale transport from both southern Chile and Burdwood Bank. By linking fish explicitly to their physical environment, the two techniques can help distinguish the life cycle trajectories necessary for populations to persist, and elucidate the interactions between hydrography and life history that structure the fish assemblages on which marine fisheries depend. © 2012 Elsevier B.V. Source

Hedd A.,Memorial University of Newfoundland | Montevecchi W.A.,Memorial University of Newfoundland | Otley H.,Falkland Islands Government | Phillips R.A.,Natural Environment Research Council | Fifield D.A.,Memorial University of Newfoundland
Marine Ecology Progress Series | Year: 2012

The distributions of many marine birds, particularly those that are highly pelagic, remain poorly known outside the breeding period. Here we use geolocator-immersion loggers to study trans-equatorial migration, activity patterns and habitat use of sooty shearwaters Puffinus griseus from Kidney Island, Falkland Islands, during the 2008 and 2009 nonbreeding seasons. Between mid March and mid April, adults commenced a ∼3 wk, >15 000 km northward migration. Most birds (72%) staged in the northwest Atlantic from late April to early June in deep, warm and relatively productive waters west of the Mid-Atlantic Ridge (∼43-55° N, ∼32-43° W) in what we speculate is an important moulting area. Primary feathers grown during the moult had average δ 15N and δ 13C values of 13.4 ± 1.8 and -18.9 ± 0.5‰, respectively. Shearwaters moved into shallow, warm continental shelf waters of the eastern Canadian Grand Bank in mid June and resided there for the northern summer. Migrant Puffinus shearwaters from the southern hemisphere are the primary avian consumers of fish within this ecosystem in summer. During migration birds flew for 78% of the day and 59% of the night, whereas when resident in the northern hemisphere they spent much of their time on the water (70% daylight, 90% darkness). Shearwaters moved south late August to mid September, completing the ∼30 000 km figure-of-eight round trip migration in ∼2 to 3 wk. The Northern Patagonian Shelf and Argentine Basin were used as a terminal stopover site, where most (79%) shearwaters spent ∼1 wk before first returning to the breeding colony for the season. Year-round tracking of seabirds aids the identification of important marine areas and highlights regions where conservation efforts need to be focused. © 2012 Inter-Research. Source

Baylis A.M.M.,Falklands Conservation | Zuur A.F.,Highland Statistics Ltd. | Zuur A.F.,University of Aberdeen | Brickle P.,Falkland Islands Government | Pistorius P.A.,Nelson Mandela Metropolitan University
Ibis | Year: 2012

Detecting and predicting how populations respond to environmental variability are eminent challenges in conservation research and management. This is particularly true for wildlife populations at high latitudes, many of which demonstrate changes in population dynamics associated with global warming. The Falkland Islands (Southwest Atlantic) hold one of the largest Gentoo Penguin Pygoscelis papua populations in the world, representing c. 34% of the global population. The numbers of breeding Gentoo Penguins at the Falkland Islands have shown a high degree of inter-annual variability since monitoring commenced in 1990. However, proximate causes of annual variability in breeding numbers have not been explored. Here we examine 21years of Gentoo Penguin breeding surveys from the Falkland Islands and assess whether inter-annual variability in the number of breeding pairs were correlated with proxies of environmental variability. There was a positive correlation between the number of breeding pairs and a broad-scale climatic variation index, the Southern Oscillation Index (SOI). In turn, the SOI was significantly correlated with spring sea surface temperature anomalies, indicating a more immediate atmospherically forced response to El Niño Southern Oscillation variability in the Southwest Atlantic than previously reported. However, we also describe a non-linear response to environmental variability that may highlight foraging plasticity and/or the complexity of regional ecosystem interactions that operate across a range of different scales. © 2011 The Authors. Ibis © 2011 British Ornithologists' Union. Source

Legua J.,Pontifical Catholic University of Valparaiso | Plaza G.,Pontifical Catholic University of Valparaiso | Perez D.,Pontifical Catholic University of Valparaiso | Arkhipkin A.,Falkland Islands Government
Latin American Journal of Aquatic Research | Year: 2013

The southern blue whiting, Micromesistius australis (Norman, 1937), is an important demersal resource associated with the slope and continental shelf of southern Chile, Argentina and the Malvinas/Falkland Islands. Recent studies have reported schools of adult fish from Atlantic waters migrating along the southern Chilean coast in mid-winter, moving northwards to spawn in August (47o-51oS), and then returning to Atlantic waters, presumably to feed. The migratory pattern suggests the presence of one or more stock units associated with the South American coast. In the present study, "otolith morphometry" is used to determine the stock structure of M. australis based on applications of basic size descriptors (SDs) (area, perimeter and otolith size), shape indices (SIs) (circularity, squareness, shape factor, roundness, ellipticity), and normalised elliptical Fourier descriptors (NEFDs). Samples were collected during the winter and spring of 2010, during the reproductive period, in the economic zone of southern Chile (36o-57oS), in the Pacific Ocean and around the Falkland Islands economic zone (50o-52oS) in the Atlantic Ocean. Analyses were conducted to include the effects of size, sex and age. A stepwise canonical discriminant analysis showed that fish were successfully discriminated with SDs, SIs and NEFDs. In this analysis, 86.4% and 70.1% of the fish were correctly classified as belonging to the Atlantic and Pacific stocks, respectively. A multivariate analysis of variance showed that the mean values of the NEFDs, SDs, and SIs did not vary significantly between sexes within areas (P > 0.05), but varied significantly between the Pacific and Atlantic oceans (P < 0.05). These results highlighted that otolith shape analysis can be a useful tool to evaluate the potential level of mixing in feeding areas where both stocks, the Pacific and Atlantic units, are expected to co-occur. Source

Otley H.,Falkland Islands Government | Smith J.,Stanley Inc. | Dalebout M.L.,University of New South Wales
Journal of the Marine Biological Association of the United Kingdom | Year: 2012

Records of beaked whales stranded in the Falkland Islands and at South Georgia were collated for the period 1866 to 2008. Thirty-eight records, involving at least seven species in four genera, were documented. Strap-toothed whales (Mesoplodon layardii Gray, 1865) were the most common species with 11 records, including two neonates. Andrews' beaked whales (M. bowdoini Andrews, 1908), Arnoux's beaked whales (Berardius arnuxii Duvernoy, 1851), Cuvier's beaked whales (Ziphius cavirostris Gray, 1823), Gray's beaked whale (M. grayi van Haast, 1876), Hector's beaked whales (M. hectori Gray, 1871) and southern bottlenose whales (Hyperoodon planifrons Flower, 1882) were recorded on three to five occasions. In several cases, records suggested potential temporal changes in range. For example, Arnoux's beaked whale has not been recorded in the Falkland Islands since 1965, whilst Gray's beaked whale was not recorded prior to 1981, and Andrews' beaked whale was not recorded before 1987. Although the number of records for each species is low, this could reflect changes in water temperatures and/or prey availability. Overall, this study confirms that the Falkland Islands-Tierra del Fuego region is one of the world's key areas for beaked whales. © 2012 Marine Biological Association of the United Kingdom. Source

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