Recovering gray whales could help recovery of declining marine birds

SeaDoc-funded research suggests that the recovering gray whale population might be important for providing food for marine birds that are in decline.

Gray whales, listed as sensitive species by Washington State and threatened by British Columbia, make an annual 10,000 mile migration between calving grounds in Baja California and summer feeding grounds in the Arctic. Every year some of them break-off their northern migration to come into shallow waters of Puget Sound to feed for extended periods.

Gray whales alter the sea floor by making large pits as they suction feed, sieving out ghost shrimp and other invertebrates. Nutritious marine invertebrates colonize gray whale feeding pits and remain abundant in these areas for extended periods.

Thanks to SeaDoc Society funding, Eric Anderson and Jim Lovvorn of the University of Wyoming recently discovered that these aggregations of invertebrates provide food for ocean-going ducks that feed on sea floor invertebrates. Feeding by gray whales along the Pacific coast between the Bering Sea and Baja, Mexico appears to be increasing and such increases could enhance feeding opportunities for scoters and other declining bottom-feeding birds during the critical spring period, when typical food is less abundant and nutritional requirements needed to prepare for migration and reproduction are high. This study appears in the current issue of the scientific journal Marine Ecology Progress Series.

This research was highlighted in the San Juan Islander and a pdf of the paper can be downloaded here.