Angling Pressure in California

Authors: Schroeder, D and Love, M
Journal: CalCOFI Rep., Vol. 43
Year: 2002
Where: University of California

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.

  • The enormous number of anglers in California - 1.7 million, with 6 million angling trips - have devastating effects on fish populations.
  • For 16 species of fish found nearest to the coast, anglers killed more fish than commercial fishermen.
  • The area only open to recreational angling had the lowest number of rockfish remaining.
  • Numbers of cowcod and bocaccio fish were an incredible 408 times higher in the protected area compared to the recreational angling area.
  • Anglers, even when they kill smaller numbers of fish, can have profound long-term effects on populations, especially when those fish are long-lived, and it may be a considerable time before the effect is realised.
  • Large quantities of litter was found in the sea from anglers: lead weight, lures, fish line, and beer cans.

"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."

Angling pressure on Rock fish

"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."

DATA GATHERING

"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."

ANGLING LITTER

"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."
Bennett, B. A. 1993. The fishery for white steenbras Lithognathus lithognathus off the Cape Coast, South Africa, with some considerations for its management. S. Afr. J. Mar. Sci. 13:1–14.
Buxton, C. D., and J. R. Clarke. 1991. The biology of the white musselcracker Sparodon durbanensis (Pisces, Sparidae) on the eastern Cape Coast, South Africa. S. Afr. J. Mar. Sci. 10:285–296.
Crooke, S. J. 1992. Giant Sea Bass. In California’s living marine resources and their utilization, W. S. Leet, C. M. Dewees, and C. W. Haugen, eds. Sea Grant Extension Publ., UCSGEP-92-12, pp.153–157.
Dayton, P. K. 1998. Reversal of the burden of proof in fisheries management. Science 279:821–822.
Jouvenel, J. Y., and D. A. Pollard. 2001. Some effects of marine reserve protection on the population structure of two spearfishing target-fish species, Dicentrarchus labrax (Moronidae) and Sparus aurata (Sparidae), in shallow inshore waters, along a rocky coast in the northwestern Mediterranean Sea. Aquat. Conserv. 11:1–9.
Karpov, K. A., D. P. Albin, and W. H. Van Buskirk. 1995. The marine recreational fishery in northern and central California. Calif. Dep. Fish Game, Fish. Bull. 176.
Love, M. S. 1978. Aspects of the life history of the olive rockfish, Sebastes serranoides. Ph.D. diss., Univ. of California, Santa Barbara.
Karpov, K. A., D. P. Albin, and W. H. Van Buskirk. 1995. The marine recreational fishery in northern and central California. Calif. Dep. Fish Game, Fish. Bull. 176.
Muoneke, M. I., and W. M. Childress. 1994. Hooking mortality: a review for recreational fisheries. Rev. Fish. Sci. 2:123–156.
Schirripa, M. J., and C. M. Legault. 1999. Status of the red snapper in U.S. waters of the Gulf of Mexico: updated through 1998. Southeast Fisheries Science Center, Sustainable Fisheries Division Contribution: SFD-99/00-75. 86 p.
Sluka, R. D., and K. M. Sullivan. 1998. The influence of spear fishing on species composition and size of groupers on patch reefs in the upper Florida Keys. Fish. Bull. 96:388–392.
Young, G. C., B. S. Wise, and S. G. Ayvazian. 1999. A tagging study on tailor (Pomatomus saltatrix) in western Australian waters: their movement, exploitation, growth, and mortality. Mar. Freshw. Res. 50:633–642.
Fish Pain