Albacore (Thunnus alalunga) fishing ground in relation to oceanographic conditions in the western North Pacific Ocean using remotely sensed satellite data

Abstract

Satellite-based oceanographic data of sea surface temperature (SST), sea surface chlorophyll-a concentration (SSC), and sea surface height anomaly (SSHA) together with catch data were used to investigate the relationship between albacore fishing ground and oceanographic conditions and also to predict potential habitats for albacore in the western North Pacific Ocean. Empirical cumulative distribution function and high catch data analyses were used to calculate preferred ranges of the three oceanographic conditions. Results indicate that highest catch per unit efforts (CPUEs) corresponded with areas of SST 18.5-21.5°C, SSC 0.2-0.4 mg m )3 , and SSHA )5.0 to 32.2 cm during the winter in the period 1998-2000. We used these ranges to generate a simple prediction map for detecting potential fishing grounds. Statistically, to predict spatial patterns of potential albacore habitats, we applied a combined generalized additive model (GAM) ⁄ generalized linear model (GLM). To build our model, we first constructed a GAM as an exploratory tool to identify the functional relationships between the environmental variables and CPUE; we then made parameters out of these relationships using the GLM to generate a robust prediction tool. The areas of highest CPUEs predicted by the models were consistent with the potential habitats on the simple prediction map and observation data, suggesting that the dynamics of ocean eddies (November 1998 and2000) and fronts (November 1999) may account for the spatial patterns of highest albacore catch rates predicted in the study area. The results also suggest that multispectrum satellite data can provide useful information to characterize and predict potential tuna habitats.

Trends in sightings and environmental influences on a coastal aggregation of manta rays and whale sharks

“…In the western Indian Ocean, 90% of whale shark sightings have been suggested to occur in a narrow surface temperature band (26.5 to 30°C) (Sequeira et al 2012). SST is likely to strongly influence whale shark sightings offshore, where fronts are a major driver of the spatial dynamics of predators (Zainuddin et al 2008, Tew Kai & Marsac 2010. The lack of a relationship with SST in our study was either because such oceanic fronts may have less influence on coastal surface waters, or because remotely sensed SST data was inadequate for our purpose.…”

Analytical approaches to investigating seabird–environment interactions: a review

“…While it is assumed that these parameters are associated with prey availability and associated oceanographic processes, the actual mechanisms responsible are rarely identified. Indeed, only during the last decade, has mesoscale dynamics in the oceans emerged as an influential factor on the distribution of seabirds (Haney 1985b, 1986a,b, 1987a,b, 1988, Nel et al 2001, Weimerskirch et al 2004, Ballance et al 2006, Hyrenbach et al 2006, O'Hara et al 2006, marine turtles (Polovina et al 2001, Lambardi et al 2008, marine mammals (Ream et al 2005, Campagna et al 2006, Biuw et al 2007, fish (Brandt 1981, Bakun 2006, Zainuddin et al 2008, squids (Rodhouse et al 1996, Waluda et al 2001, zooplankton (Huntley et al 2000, Labat et al 2002, Strzelecki et al 2007), phytoplankton and marine production (McGillicuddy et al 1998, Martin 2003, Mitchell et al 2008.…”

Ocean observatory data are useful for regional habitat modeling of species with different vertical habitat preferences

“…The data describe the physical forcing, current flows, and sources and transport of detritus, primary and secondary productivity which structure, couple and fuel coastal ocean habitats and thus regulate the recruitment of animals using them. Remotely sensed data have been used to construct habitat models for open ocean pelagic predators, but are not commonly used for coastal species (Valavanis et al 2008, Zainuddin et al 2008, Becker et al 2010, Mugo et al 2010, Zydelis et al 2011.…”