Julie van der Hoop, Biology


Potential chemical cues released from whale tissue

The deep sea is known to be sparse of nutrients, though large food deposits such as whale carcasses can provide significant energy and habitat resources on unpredictable timescales. Though primarily described as important to deep-sea ecosystems, it has been suggested that whale and other food falls may provide supplementary nutrition to coastal ecosystems as well. Based on extremely high mortality of large whales in the coastal North Atlantic, the density of whale falls may be much higher than expected in coastal waters, and as such may provide a greater food resource to the benthic community than has been previously considered.

It remains a mystery how scavenging and settling organisms locate and exploit whale falls. My research funded by the Coastal Ocean Institute focuses on identifying the chemical signature that may be specific to whale falls. This research, completed at WHOI, was made possible by WHOI’s Marine Mammal Center and its collaboration with local marine mammal stranding networks (IFAW). Available tissue samples from stranded whales were submerged in seawater and decomposition processes were monitored. Then, using High Performance Liquid Chromatography (HPLC), it is possible to determine the composition and concentrations of amino acids present in seawater surrounding decomposing whale material, acting as cues to specialist species.

Determining the presence and distribution of these chemical signals will provide insight into the chemical ecology of specialist organisms, the patterns they exhibit, and their long-term effects on the deep-sea benthos. Further, it excites the potential to detect these cues using AUV technology and to search out whale fall sites. Discovery of whale falls in the Northwest Atlantic has large implications on current standing hypotheses of deep-sea biogeography of chemosynthetic habitats.