This research looked at the severe effects that anglers have on fish living off the Californian coast. A small submarine was used, and information was taken from a 6-year survey. Areas of the sea were designated as: commercial and recreational angling; recreational only; or protected from all fishing.
"Recreational and commercial fishers target many of the 70 species of rockfish that inhabit the northeastern Pacific. Most of these exploited rockfish species are long-lived."
"A comparison of rockfish assemblages among three differently fished areas (one open to all fishing, another open only to recreational fishing, and a de facto marine protected area) revealed large differences in fish density, size structure, and species composition."
"The area open only to recreational fishing had the lowest rockfish density (423 fish/ha) and a size structure also dominated by small fishes."
"Two species federally listed as over fished, cowcod and bocaccio, had 32-fold and 408-fold higher densities, respectively, in the de facto reserve than observed inside the recreational fishing area."
"For 17 nearshore fish species, we compared landings by recreational anglers and commercial harvesters and found that, for 16 species, recreational angling was the primary source of fishing mortality. We illustrate the potential damaging effects of mortality associated with catch-and-release programs on long-lived fish populations. Based on this information, we recommend that legislators and natural resource managers reject the assumption that recreational fishing is a low or no impact activity."
ANGLERS INTO POPULATION DESTRUCTION
"By seeking to maximize fishery yields, traditional fisheries management places most of this risk burden onto fish populations (Dayton 1998). Such a tendency has been injudicious because (1) fisheries can be overexploited before managers and scientists have sufficient data to indisputably document declining population trends, and (2) over exploited fisheries rarely recover after collapse."
SMALL INCREASES IN MORTALITY DUE TO ANGLING CAN BADLY AFFECT FISH POPULATIONS
"We also illustrate how small increases in mortality associated with catch-and-release programs can affect long-lived fish populations."
"We extracted data from a six-year survey of fishes living on deep natural outcrops and around oil platforms within the Southern California Bight. To quantify fish abundance and associated habitat, we used the Delta, a two-person submersible."
"While performing fish surveys at the Footprint, we observed large amounts of gear debris (traps, longlines, trawl nets, and gill nets) from commercial fishing and many dislodged or damaged sponges. Evidence of recreational fishing activity (lead weights, artificial lures, monofilament line, and Budweiser beer cans) was also commonly encountered at the Footprint."
EXCUSE OF POLLUTION AND OCEAN CHANGES
BY ANGLERS DO NOT HOLD UP
"Two alternatives frequently suggested by stakeholders as the primary cause of declining rockfish populations are high pollution levels and changing oceanographic conditions. There is no scientific evidence that pollutants in the Southern California Bight appreciably affect population dynamics of rockfishes."
ANGLERS KILLING MORE FISH THAN COMMERCIAL FISHERMEN
"It remains clear that in the aggregate, recreational fishers impacted nearshore populations more than commercial harvesters."
"Recreational anglers dominate other fisheries that show signs of depletion. Karpov et al. (1995) report that total surfperch landings from northern and central California during the period 1981–86 were 240 metric tons for recreational fishing and 56 metric tons for commercial harvesters."
MATURE OLIVE ROCKFISH POPULATION DEVASTATED
"On localized rocky outcrops, depletion in olive rockfish populations has been described by Love (1978), who found a complete lack of mature individuals in areas heavily fished by recreational anglers; lightly fished areas had many mature fish."
"Fish that have been hooked, landed, and released by anglers may still die from tissue trauma, bacterial infection, or increased vulnerability to predation resulting from a catch-and-release event (Muoneke and Childress 1994)."
A CONSERVATIVE ESTIMATE OF 20%
MORTALITY PREDICTED TO CAUSE EXTINCTION
"After 25 years, 29 giant sea bass remained alive in the baseline population; the addition of any catch-and-release mortality changes this number considerably. A 20% catch-and-release mortality rate causes extinction of the giant sea bass population after 16 years."
ANGLING HAS A LARGE IMPACT ON FISH POPULATIONS
"In California waters, the view that recreational angling has no or little impact on marine populations is not supported by the best scientific information available. Our results agree with other reports that find recreational anglers capable of measurably impacting marine resources (Buxton and Clarke 1991; Bennett 1993; Sluka and Sullivan 1998; Young et al. 1999; Jouvenel and Pollard 2001). California has the third largest number of recreational anglers in the United States, with approximately 1.7 million anglers making nearly 6 million fishing trips during 2000 (Marine Recreational Fisheries Statistical Survey database). With such large numbers of fishers pursuing limited numbers of fish, the results we present here are not unexpected."
"Our findings also suggest that recreational angling may be incompatible with some common goals of spatial closures, such as protecting marine ecosystem structure, and establishing scientific control and marine wilderness areas. Large predators may disappear when a reef is fished even lightly, and this in turn may alter ecosystem structure through top-down, trophic cascades (Dayton et al. 1995; Boehlert 1996; Pinnegar et al. 2000). Local depletion of California sheephead and subsequent changes in sea urchin and giant kelp dynamics may be an example of this phenomenon (Pinnegar et al. 2000)."
DIFFICULT FOR FISH TO RECOVER
"Many of California’s exploited marine species possess life history traits (e.g., long life or irregular juvenile recruitment) that may inhibit timely population recovery once overfishing occurs."