Surveys for Beached Marine Mammal and Seabird Carcasses: Annual Progress Report

Holm, Greg

Excerpts: "Beached carcass surveys are performed to ascertain baseline information about seabird and marine mammal mortality that occurs along the Redwood National and State Parks (RNSP) coastline. The main objectives are to gather trend data on mortalities, and determine whether the mortalities resulted from natural or anthropogenic events. Documenting natural mortalities can help biologists monitor events such as the expected death of post-fledging and adult breeding seabirds, fatal injuries from predation and other natural hazards, and diseases in a population. Also, population effects of natural events (e.g. El Nino) can be monitored more effectively. The presence of petroleum products on carcasses can provide information on 'background' levels of these contaminants in the marine system. In addition, baseline data on the presence (or absence) of petroleum products on wildlife can be valuable for comparison when a large scale spill does occur. Entanglement in fishing gear and human trash, such as plastic bags and six-pack rings, has been documented as a cause of death for some marine fauna, and is also monitored for frequency of occurrence within RNSP. Freshwater Spit and Gold Bluffs Beach (north and south stretches) were both surveyed for beached carcasses during January, and December 2003. All Redwood National and State Park beaches were surveyed once per month for beached carcasses during March through October 2003. From March through October of 2003 (and 2002), all carcasses that were detected on RNSP beaches during surveys were marked with a piece of red biodegradable flagging (tied onto animal in best location for retention). Nineteen carcasses were detected during winter surveys. Five hundred and seven carcasses were detected [during non-winter surveys]." Includes information on species of seabirds and marine mammals detected, a discussion, and future survey recommendations. Appendices include maps of beach stretches surveyed, beach carcass survey protocol, and a data form.