Selenium and Boron in Aquatic Birds from Central California

A robust collection of mammal, bird, fish, and shellfish remains from an 8,000-year residential sequence at Morro Bay, a small, isolated estuary on the central California coast, shows a strong focus on marine species during the Middle-Late Transition cultural phase (950–700 cal B.P.), which largely coincides with the Medieval Climatic Anomaly (MCA). Previous studies have provided modest evidence for increased fishing and rabbit hunting during the MCA in adjacent regions, but the Morro Bay findings suggest a distinctive marine-focused subsistence refugium during the period of drought. Specifically, the sequence shows striking all-time peaks in marine and estuarine birds, fish NISP/m3, and fish/deer + rabbits during the MCA. Heavy exploitation of fish, aquatic birds, rabbits, and shellfish suggests that the bow and arrow, which seems to have arrived in the area at this time, had little impact on local subsistence strategies.

Download Full-text

Delineating Long-Term Trends in Beach Change, Central California

California and the World Ocean '02 ◽

10.1061/40761(175)3 ◽

2005 ◽

Author(s):

Cope M. Willis ◽

Gary B. Griggs

Keyword(s):

Central California ◽

Long Term Trends

Download Full-text

Effects of marine reserves on predator-prey interactions in central California kelp forests

Marine Ecology Progress Series ◽

10.3354/meps13526 ◽

2020 ◽

Vol 655 ◽

pp. 139-155

Author(s):

DC Yates ◽

SI Lonhart ◽

SL Hamilton

Keyword(s):

Species Interactions ◽

Size Structure ◽

Marine Reserves ◽

Mortality Rates ◽

Kelp Forests ◽

Negative Effects ◽

Central California ◽

Invertebrate Predators ◽

Predatory Fishes ◽

Density And Biomass

Marine reserves are often designed to increase density, biomass, size structure, and biodiversity by prohibiting extractive activities. However, the recovery of predators following the establishment of marine reserves and the consequent cessation of fishing may have indirect negative effects on prey populations by increasing prey mortality. We coupled field surveys with empirical predation assays (i.e. tethering experiments) inside and outside of 3 no-take marine reserves in kelp forests along the central California coast to quantify the strength of interactions between predatory fishes and their crustacean prey. Results indicated elevated densities and biomass of invertebrate predators inside marine reserves compared to nearby fished sites, but no significant differences in prey densities. The increased abundance of predators inside marine reserves translated to a significant increase in mortality of 2 species of decapod crustaceans, the dock shrimp Pandalus danae and the cryptic kelp crab Pugettia richii, in tethering experiments. Shrimp mortality rates were 4.6 times greater, while crab mortality rates were 7 times greater inside reserves. For both prey species, the time to 50% mortality was negatively associated with the density and biomass of invertebrate predators (i.e. higher mortality rates where predators were more abundant). Video analyses indicated that macro-invertivore fishes arrived 2 times faster to tethering arrays at sites inside marine reserves and began attacking tethered prey more rapidly. The results indicate that marine reserves can have direct and indirect effects on predators and their prey, respectively, and highlight the importance of considering species interactions in making management decisions.

Download Full-text