Abundance, habitat use and movement patterns of the shovelnose guitarfish (Rhinobatus productus) in a restored Southern California estuary.

摘要

Shovelnose guitarfish (Rhinobatos productus) seasonally use bays and estuaries for mating, pupping and feeding. Monthly abundance surveys were conducted inside the restored Full Tidal Basin (FTB) of Bolsa Chica, California between June 2008 and September 2009. A total of 269 shovelnose guitarfish (96% immature) were captured using beach seines and longlines. Shovelnose guitarfish were present all year, with a decrease during the winter months. Concurrently, 23 shovelnose guitarfish were fitted with acoustic transmitters and tracked within the FTB. Telemetry data showed individuals remain on average 73.9 d inside the FTB and establish home ranges representing 12% of the FTB area. Tagged shovelnose guitarfish disproportionately used muddy habitats and 22ºC waters, both of which are more common in the FTB than the neighboring coastal ocean. This study suggests that the restored FTB is important habitat for the feeding and growth of juvenile shovelnose guitarfish, a promising result after 3 years post-restoration.