Bachelor of Science (B.S.)
Science & Environmental Policy
ith the recent boom in the live-fish industry, nearshore ecosystems that were once relatively unfished are now experiencing heavy fishing pressure. From 1994 to 1998, live-fishery landings for the state of California went from estimated values of 408 metric tons (MT) to 670 MT, an increase of 64%. The cabezon (Scorpaenichthys marmoratus) was first targeted by live-fishermen in 1994. Since then fishing pressure has been on the rise. From 1996 to 1997 there was a 115% increase in cabezon landings. In 1998 the cabezon became the number one catch in the live-fishery, totaling 152 MT at a value of approximately $1 million. In response to the live-fishery, the Nearshore Fisheries Management Act was passed in 1998, instituting a minimum size limit for cabezon of 356 mm that became effective in January 1999. At this time there is only minimal management of the live-fishery and cabezon in particular. This is due in part to insufficient knowledge of species habitat associations and how they change with age. Without understanding the abundance of the species in its preferred habitat it is difficult to make management decisions. This study sought to quantify the depth and substrate preferences of sexually immature, preadult cabezon. Twenty-four 60 m video transects were run using SCUBA across three depth zones (0-6 m, 6-12 m, 12-18 m) at Point Lobos Marine Reserve near Monterey, California. A total of five fish were observed, with the deepest and largest being a 558 mm fish at 7.3 m depth. The other four fish were at slightly shallower depths, and ranged in size from 352 to 391 mm in length. The data was analyzed using the Kruskal-Wallis nonparametric statistical test and no clear distinction of depth preferences was revealed. A second set of data collected by a Carmel High School class in the Spring of 1999 was also analyzed using Kruskal-Wallis. These data did show a difference in depth strata but there was no stratification for depth during sampling, and thus the samples are extremely unbalanced. There is no indication from these data sets that preadult and adult cabezon are segregated by depth. In addition to the field study, an examination of fisheries management policies was conducted to address knowledge of cabezon life history traits learned from the literature, and from the observations and results of this study.
Castleton, Michael Ross, "Depth and substrate preferences of preadult cabezon (Scorpaenichthys marmoratus) in Point Lobos Marine Reserve" (2000). Capstone Projects and Master's Theses. 128.