Foraging landscape of the Hawaiian monk seal

Habitat and fish assemblages of the Northwestern Hawaiian Islands were compared with movement patterns of the endangered Hawaiian monk seal. The seals' foraging pattern could not be attributed to the area, distance or effort associated with feeding in reef, bank, slope or subphotic habitats. Seals did not target areas with the largest fish body size, fish number, or fish biomass. Comparing the fish assemblages with the fish guilds seals' are known to eat (derived from scat studies) indicated the fish composition of the bank and slope habitats were the most similar to the seals' diet.; Submersible surveys of areas with and without deepwater corals, were conducted to see if greater fish density, size or biomass were found near deepwater corals. Areas with tall morpho-types of deepwater corals (e.g. Gerardia sp.) often supported greater fish densities than adjacent areas without deepwater corals. The guild "benthic hoverer" was the most commonly seen fish using the coral branches as shelter. However, an analysis of fish and coral data accounting for habitat effects indicated fish and deepwater corals co-occur in areas of high relief, each likely exploiting improved flow conditions, with little inter-dependance.; Fish data were compared with indices of regional primary productivity and insular predation pressure (including monk seals) from the euphotic zone. Fish density and biomass weakly agreed with a 3-region model based on satellite sea-surface temperature measurements. However, this relationship was excluded as not significant from a multiple regression model that considered insular predation pressure, in particular monk seals. The size of the nearest colony and its distance from the station best explained the variance in fish biomass at the subphotic stations surveyed. This suggests that seal populations and perhaps other species from shallow insular ecosystems are significant subphotic predators and influence the structure of subphotic fish communities.