Brenton Spies

Dr. Mark Steele's Fish Ecology Lab

Department of Biology
18111 Nordhoff Street
Northridge, CA 91330-8303

Education: B.S. Biology, San Diego State University 2008

M.S. Thesis

Latitudinal variation in the early life history of the arrow goby, Clevelandia ios, and the endangered tidewater goby, Eucyclogobius newberryi: implications for conservation in estuarine fish metapopulations

Estuaries in California are highly variable transitional zones of the coastal marine environment. Factors such has temperature, annual precipitation, and freshwater input vary among estuaries and can affect the dynamics of each estuary and the species that inhabit it. This variation in the environment has been found to strongly influence the life history of many marine organisms with large latitudinal gradients. Species such as the endangered tidewater goby (Eucyclogobius newberryi) may be predisposed to local extirpation due to their preference for seasonally variable estuaries. The tidewater goby generally inhabits estuaries that contain somewhat persistent low-salinity and highly variable temperatures depending on the duration of habitat closure. These habitats are heavily impacted by anthropogenic effects, limiting the amount of suitable habitat this species needs for recovery. This preference differs from that of its closest relative, the arrow goby (Clevelandia ios), which inhabits cooler, higher salinity estuaries that are less impacted by anthropogenic effects. My study looks to better understand how environmental factors affect early life history traits such as pelagic larval duration (PLD), size at settlement, and post-settlement growth rates using these two estuarine species. With the increased loss of critical habitat along the California coast, it is important to understand how variations in environmental factors shape the dynamics of populations and communities.