Organisms in the deep-sea are highly food-limited, relying primarily on organic matter falling from above. Large animal remains are quickly exploited by mobile local fauna. These and other sources of concentrated, imported, organic matter---pulses of phytoplankton, drifting seaweed and wood---permit niche diversification and thus co-existence of extraordinarily high numbers of species within the otherwise food-impoverished, relatively homogeneous, deep-sea environment [e.g., Grassle and Maciolek, 1992].
Whale carcasses may be particularly important to the deep sea because their large bodies sink fast enough to transit thousands of meters of water, containing fish and other planktonic scavengers, with sufficient tissue intact for exploitation by seafloor-dwelling organisms. An exciting discovery in 1987, however, indicates that deep-sea community diversity is also enhanced by the decaying whale skeleton [ Smith et al., 1989]. A whale skeleton on the deep-sea floor was observed to support an invertebrate community nourished largely by endosymbiotic chemoautotrophic bacteria, typical of hydrothermal vents and other deep-sea reducing habitats. Whale skeletons scattered here and there like islands throughout the deep ocean basins may thus facilitate temporal and spatial dispersal of some organisms previously considered obligate to hydrothermal-vent fields, providing critical stepping stones between these unique communities which, themselves, are insular habitats (Figure 1).
Given the potentially important role of dead whales to the deep sea, these communities may have been altered by the booming whaling industry, prior to serious international intervention beginning in the mid-1960s [ Butman et al., 1995]. Whaling may have affected whale-carcass supplies to the deep sea in two ways (Figure 1). First, up until the turn of the 20th century, enhanced numbers of cast-off whale skeletons may have been concentrated on the bottom in geographic regions of favorable whale hunting, changing the natural distribution of whale carcasses on the deep-sea floor. A second, and perhaps more profound effect would be from the decrease in supply of whale skeletons beginning in the early 1900s. This was when new whale-processing technology permitted the use of whale bone for oil, bone meal and fertilizer, so whale skeletons were no longer discarded.
A greatly reduced---and in some regions, no---whale skeleton supply to the deep sea would result in a severe spatial interruption, if not obliteration, of stepping stones between hydrothermal vents and other chemoaut-otrophic-based communities. Dissolution of dispersal corridors between vent fields could alter hydrothermal faunas, and thus, biological diversity in vent and seep areas. But, the magnitude and consequences of changes in deep-sea biodiversity resulting from whaling are difficult to evaluate because of the lack of historical or even good contemporary data on most whale population sizes and distributions, because the region impacted is far removed from the disturbance source, and because effects are being considered nearly a century after-the-fact.