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Earlier in this bulletin we described the importance of surfperch (family Embiotocidae) to the catch of the shore-based modes during both the 1958-61 and 1980-86 survey periods (Figure 6; Figures 14-17). The surfperch were also the only major species category where both sport and commercial catch decreased substantially between the two surveys (Figure 5). Of the 21 species in the surfperch family, 19 are found in California (Eschmeyer et al. 1983). Seventeen of those were found in the 1980-86 MRFSS creel surveys in northern and central California (Table 9). The more commonly taken species were barred surfperch, redtail surfperch, silver surfperch, walleye surfperch, striped seaperch, white seaperch, shiner perch, and pile perch. Our analysis focuses on those species. Black perch and rubberlip seaperch were relatively uncommon but were included in some analysis.
The surfperch family ranges mainly from subtropical Baja California to subarctic Alaska; two species are found in the Sea of Japan and one California species is restricted to freshwater (Tarp 1952). The primary factor affecting distribution is temperature. Southern California is the latitudinal center of distribution (Tarp 1952). Of the 18 species found in California marine waters, eight have northern range limits and one has a southern range limit in northern and central California. The other species have northern limits north of California and southern limits in southern California or Baja California (Table 9).
Common names of the surfperches indicate habitats they frequently use (Table 9). "Surfperch" generally use sandy and rocky surf areas, "seaperch" generally use kelp forests and open ocean reef areas, and "perch" use a variety of habitats (McClane 1965). The naming convention is not entirely indicative of habitat use, and habitat use may also change during mating and birthing.
Life history differences within the surfperch are many, and include differences in growth rate, longevity, fecundity, breeding habitat, age at first reproduction, and size of young. Surfperch are viviparous and have low fecundity with an average brood size of 15 (Table 9). Newborn are large (3-6 cm long) (Odenweller 1975; Behrens 1977) and highly developed (Eschmeyer et al. 1983). Females of many species generally migrate to bays and estuaries, if available nearby, presumably to give birth (Gordon 1965; Bennett and Wydoski 1977; DeMartini et al. 1983).
Some species use eelgrass (Zostera spp.) beds in estuaries for birthing and nursery habitat. The birthing period varies among species but generally occurs in spring and early summer (Hubbs 1921; Turner 1938; Lagios 1965; Odenweller 1975), with birthing delayed with increasing latitude. Age at sexual maturity varies. Dwarf seaperch males are mature at birth (Hubbs 1921); other species reach maturity as late as the third year.
Surfperch are a significant trophic component of many nearshore marine habitats, where they glean small invertebrates and fish eggs from substrates (Carlisle et al. 1960; McClane 1965; Odenweller 1975; Bennett and Wydoski 1977; Ellison et al. 1979). Habitats used by various species include sandy beaches, rocky reefs and inlets, kelp forests, and estuaries. In the spring months, juvenile and adult surfperch consume breeding adult and larval stages of sand crabs (Emerita analoga) over sandy beaches (Ricketts and Calvin 1939; Morris et al. 1980). In winter and spring, young surfperch in estuaries may feed on herring and silverside eggs deposited on eelgrass or other substrates (Carlisle et al. 1960; Hardwick 1973). Shiner surfperch in Anahiem Bay feed primarily on zooplankton (Odenweller 1975). Surfperch are eaten by piscivorous fish, marine mammals, birds, and humans.
The prevalence of surfperch in the catch of shore fisheries (Figures 7, 14-17) attests to their nearly exclusive use of relatively shallow nearshore habitats that includes bays and estuaries (Figure 56). The depth distribution of most species is limited to waters less than 100 m deep, and many are limited to waters less than 30 m deep (Table 9).
The surfperch family is divided into two subfamilies, the Amphistichinae and the Embiotocinae (Table 9), which differ morphologically in the joining of prefrontal bones, in the male anal fins and glands, and in the female ovarian structure (Tarp 1952; Hopkirk 1962). Males of the Embiotocinae have a specialized flask-shaped anal gland that contains sperm during the breeding season. In some species of the Embiotocinae, males accompany females to birthing areas, mating occurs immediately after birthing, and females store sperm for several months before fertilization occurs (Hubbs 1921; Gnose 1967; Warner and Harlan 1982) (Table 9). The use of estuaries by males tends to be more common in the Embiotocinae than the Amphistichinae (Brookins MS[a]). In the 1980-86 MRFSS, the Embiotocinae were more frequently caught in bays and estuaries than the Amphistichinae, and the converse was true in the open ocean (Figure 56). Except for shiner perch, catch of the Embiotocinae in bays and estuaries peaked in the winter and spring months. Among the Amphistichinae, barred surfperch, redtail surfperch, and silver surfperch were taken more frequently in the ocean than in bays and estuaries, but 58% of the walleye surfperch were taken in bays and estuaries.
Between the 1958-61 and 1981-86 surveys, surfperch average weights and catches declined (Figure 57). The average annual catch of surfperch, excluding the San Francisco Bay PRB fishery, dropped from 1,254,000 fish to 761,000 fish (-39%); the average annual catch by weight declined from 420 to 193 MT (-54%) (Table 10). The percentage of surfperch in the hook-and-line sport catch dropped from 48% to 29% from piers and docks and from 72% to 55% from other shore locations. The downward trend in catch was due mainly to reductions in barred surfperch, redtail surfperch, shiner perch, silver surfperch, and walleye surfperch (Table 10). Two of the most important species by number and weight in 1958-61 and 1981-86, barred surfperch and redtail surfperch, had the largest reductions in weight landed. However, catches of pile perch, black perch, and rubberlip seaperch increased.
Between the 1958-61 and 1981-86 surveys average weight per surfperch caught, excluding San Francisco Bay, declined from 0.34 to 0.25 kg/fish. Decline in size occurred among barred surfperch, redtail surfperch, striped seaperch, rubberlip seaperch, and white seaperch (Figure 57). Redtail surfperch, the second most important species in number and weight landed, had the greatest decline in size from 0.82 to 0.33 kg/fish. The dominant species, barred surfperch, declined from 0.45 to 0.30 kg/fish.
Several factors may have contributed to the decline in surfperch landings and sizes including low fecundity, degradation of estuarine nursery areas (Carlisle et al. 1960), and increases in natural or fishing mortality (Ricker 1975). The low fecundity of surfperch reduces the possibility of strong year-classes (Carlisle et al. 1960). Royce (1975) warned that species with low fecundity have limited recruitment potential and are more vulnerable to overharvest than highly fecund species.
Surfperch declines may also be caused by loss of nursery and nearshore habitat along coastal California. Destruction of habitat and pollution of inshore areas has occurred (California Coastal Commission 1987), but their effect on surfperch populations has not been quantified.
The average annual recreational catch of all surfperch species in 1981-86, including San Francisco Bay PRB fishing, was 875,000 fish weighing 240 MT (Tables 11 and 12). The top species by number caught were barred surfperch, shiner perch, walleye surfperch, and pile perch. The top species by weight caught were barred surfperch, pile perch, rubberlip seaperch, and redtail surfperch. Large portions of the catch came from San Francisco Bay and the Santa Cruz/Monterey district. Surfperch were caught mainly from shore-based modes (85%) (Table 11). PRBs accounted for most of the remaining catch. Relatively few surfperch were caught by the spear mode (1%) and fewer by CPFV anglers.
The mean weight of all surfperch declined in a north-south gradient from 0.33 kg/fish in Del Norte/Humboldt to 0.22 kg/fish in San Luis Obispo (Table 12); the gradient was somewhat evident within individual species. The mean weight of surfperch from all districts ranged from 0.04 kg/fish (shiner perch) to 0.68 kg/fish (rubberlip seaperch). The mean weight also varied by fishing mode (Table 11). Spear mode averaged 0.58 kg/fish, followed by PRB (0.40 kg/fish), beach and bank (0.29 kg/fish), jetty and breakwater (0.28 kg/fish), CPFV (0.22 kg/fish) and pier and dock (0.18 kg/fish). The spear mode may have had the highest weight per fish because larger fish can be selected. The pier and dock mode may have had the lowest weight per fish due to the predominance of shiner perch in San Francisco Bay catches.
The species composition of surfperch in the 1980-86 MRFSS-sampled catch varied by fishing mode and latitude. In the beach and bank fishery, barred surfperch, silver surfperch, walleye surfperch, and calico surfperch were the major species of surfperch in central California, while redtail surfperch and striped seaperch were the major species in northern California (Figure 14). In the jetty and breakwater fishery, the main species were walleye surfperch in central California and striped seaperch in northern California (Figure 15). In the pier and dock fishery, walleye surfperch, shiner perch, and barred surfperch were the major surfperch species in central California, while walleye surfperch, white seaperch, shiner perch, striped seaperch, silver surfperch, and pile perch were the main species in northern California (Figure 16). The spear fishery took mainly pile perch, black perch, and striped seaperch in central California, while striped seaperch was the main species in northern California (Figure 17). PRB catch was mainly in San Francisco Bay, and consisted mostly of rubberlip seaperch, walleye surfperch, shiner perch, and pile perch (Table 11). In the CPFV fishery, where surfperch were rarely taken, a few black perch and striped seaperch were sampled in central and northern California respectively.
We developed distribution maps for the top eight surfperches using the percent of catch by number from the 1980-86 California and Oregon MRFSS data (Figures 58-60). We classified the surfperches into three categories of latitudinal distribution: 1) northern, 2) coastwide, and 3) southern. Northern species were those generally found only north of Point Conception: striped seaperch, silver surfperch, and redtail surfperch. Coastwide species were those that did not appear bounded to the north or south in Oregon and California: pile perch, shiner perch, walleye surfperch, and white seaperch. Southern species were generally found south of Cape Mendocino; barred surfperch was the only southern species.
Striped seaperch were taken from Los Angeles County northward through Oregon (Figure 58). The highest annual average percentage of total sampled catch in California occurred in Del Norte/Humboldt (5.9%), and the highest annual average in all districts occurred in Northern Oregon (6.6%). The highest annual percentage of sampled catch occurred in southern Oregon in 1985 (14.8%). Occurrence in the creel survey south of San Luis Obispo County was relatively low, and they were absent there after 1983.
Striped seaperch were found mostly in bays and estuaries (59%) (Figure 56), where capture peaked in March and May. Secondary peaks occurred in early summer in some years. Occurrence in Mendocino/Sonoma bays and estuaries dropped steadily from 156 fish in 1981 to none in 1986. The Del Norte/Humboldt and Mendocino/Sonoma districts accounted for 71% (32,000 fish weighing 14 MT) of the estimated total catch of striped seaperch (Table 12). The highest IRIs for striped seaperch were in shore and diver modes north of San Francisco (Figures 14-17).
Silver surfperch were found in catches from Orange County northward through Oregon (Figure 58). The highest annual average percentage of total sampled catch in California occurred in Del Norte-Humboldt (2.2%). Northern Oregon had the highest annual average percentage of all districts (3.0%), and the highest single-year percentage (5.9% in 1983). Occurrence south of San Luis Obispo County was relatively low, and none were sampled south of Santa Barbara/Ventura after 1983.
Most silver surfperch sampled were from the open ocean (74%) (Figure 56). Peak catch in the ocean was in April and in the bays in March. Catch in bays and estuaries was mainly in Humboldt and San Francisco bays, while catch in the open ocean was mainly in San Luis Obispo County. The San Francisco district (ocean and bay) accounted for 42% (29,000 fish weighing 5 MT) of the total catch of silver surfperch (Table 12). The highest IRIs were in beach/bank mode from San Francisco southward (Figure 14) and in the pier and dock mode in all districts except Mendocino/Sonoma (Figure 16).
Redtail surfperch were found in catches from San Luis Obispo northward through Oregon (Figure 58). The highest annual average percentage of total sampled catch in California occurred in Del Norte/Humboldt (11.6%). Northern Oregon had the highest single-year percentage of all districts (37.0% in 1981) and the highest average annual percentage (19.0%). Occurrence from Santa Cruz through San Luis Obispo counties was relatively low, with no fish in 1983, 1985, or 1986. The southern range limit reported by Miller and Lea (1972) is Monterey. The 27 fish sampled in San Luis Obispo County in the MRFSS support the species' range extension southward to Avila, as reported by Dentler and Grossman (1980).
Redtail surfperch were sampled mainly from the open ocean (71%) (Figure 56), where catch peaked in May and July-September. Catch in bays and estuaries peaked in January-March. The Del Norte/Humboldt district accounted for 45% (30,000 fish weighing 12 MT) of the total catch, and 98% (66,000 fish weighing 21 MT) of the total was from the San Francisco district northward (Table 12). The highest IRIs were from beach and bank mode from San Francisco northward and were particularly high in the Del Norte/Humboldt district (Figure 14).
The number of redtail surfperch sampled annually decreased 77% between 1980 and 1986. The decline averaged 21% per year, and was steepest between 1982 and 1983 (32%) during the ENSO. After 1983, redtail surfperch continued to decline in catches off California (Figure 58). The most dramatic decline occurred in the Mendocino/Sonoma and San Francisco districts where the number sampled in the creel survey decreased from 298 fish in 1981 to only 20 fish five years later. Occurrence in bays and estuaries in those districts declined from 154 fish in 1980-83 to only one fish in 1984-86. An exception to the general decline was the bay and estuarine catch in the Del Norte/Humboldt district, which remained stable. Disappearance of redtail populations in Humboldt Bay and in Oregon estuaries has been observed in recent years (P. Collier, CDFG, pers. comm.; Brookins MS[b]). Redtail surfperch are the main surfperch taken commercially in northern California.
Pile perch were sampled throughout California and Oregon (Figure 59). The highest annual average in California occurred in the San Francisco district (1.2%). Northern Oregon had the highest annual average of all districts in both states (6.3%), and the highest single-year percentage (11.4% in 1986). Occurrence was patchy in the Mendocino/Sonoma, Santa Barbara/Ventura, Orange, and San Diego districts.
Pile perch were caught mainly from bays and estuaries (79%) (Figure 56). Catch peaked in February. The San Francisco district accounted for 92% (73,000 fish weighing 40 MT) of the estimated total catch of pile perch with 77% (61,000 fish weighing 31 MT) from within San Francisco Bay (Table 12). The highest IRIs for pile perch were for the pier mode in Humboldt/Del Norte (Figure 16) and spear fishing from Santa Cruz through San Luis Obispo districts (Figure 17).
Shiner perch were sampled throughout California and Oregon (Figure 59). The highest annual average percentage in the creel survey in California and Oregon occurred in the San Francisco district (4.3%) (Figure 59). Del Norte/Humboldt had a relatively high annual average percentage (2.2%) and the highest single-year percentage (7.6% in 1980). Occurrence south of the Santa Barbara/Ventura district was relatively low.
Shiner perch were taken mainly from bays and estuaries (85%) (Figure 56). Catch peaked in July (Figure 57). San Francisco Bay accounted for 79% (82,000 fish weighing 3 MT) of the total catch (Table 12). The highest IRIs were from the pier mode (Figure 16).
Walleye surfperch were sampled throughout California and Oregon (Figure 59). The highest annual average percentage of total sampled catch in California occurred in Del Norte/Humboldt (3.5%). Southern Oregon had the highest annual average of both states (4.6%) and the highest annual percentage (12.4% in 1982). Occurrence in Mendocino/Sonoma was relatively low.
Walleye surfperch were taken by anglers mainly in bays and estuaries (56%) (Figure 56) where occurrence peaked in August. Capture in the ocean peaked in May and July and in August in bays and estuaries. Bay and estuarine occurrences were mainly from Humboldt and San Francisco bays. Open ocean occurrences were mainly in the Santa Cruz/Monterey district. The San Francisco district accounted for 56% (54,000 fish weighing 12 MT) of the estimated total catch of walleye surfperch (Table 12). The highest IRIs were in beach/bank and pier modes throughout northern and central California and in jetty/breakwater mode in the Santa Cruz/Monterey district (Figures 14, 15, and 16). The annual number of walleye surfperch sampled decreased 72% between 1980 and 1986.
White seaperch were sampled throughout California and Oregon (Figure 60). Del Norte/ Humboldt had the highest annual average percentage of total sampled catch (2.53%) and highest annual percentage (6.08% in 1980). Occurrence in San Luis Obispo County was patchy.
White seaperch were taken mainly from bays and estuaries (73%) (Figure 56), especially from Humboldt and San Francisco bays. In January-March, catch in bays and estuaries peaked. Catch was lowest in the ocean in March, so this species probably enters bays and estuaries to spawn at that time. Catch in the ocean peaked in January and in May, mainly in the Santa Cruz/Monterey district. The number of white seaperch sampled annually decreased 61% between 1980 and 1986; a decline occurred each year except between 1985 and 1986. The San Francisco district accounted for 64% (30,000 fish weighing 7 MT) of the estimated total sport catch of white seaperch (Table 12). The highest IRIs for the species were from pier mode, with the highest value coming from Del Norte/Humboldt (Figure 16). White seaperch were formerly the most important commercial surfperch species in the state (Tarp 1952), but are no longer a significant component.
Barred surfperch were not found in Oregon MRFSS samples, and in California were found only from Mendocino/Sonoma southward (Figure 60). Santa Cruz/Monterey had the highest annual average percent of total catch (4.5%) and the highest single-year percentage (10.0% in 1981). Occurrence in Mendocino/Sonoma was relatively low.
Barred surfperch were taken mainly from the ocean (92%) (Figure 56), where catch peaked in May-June and August-September. The creel survey data show that those peaks were sporadic, occurring in only three of the seven years. The minor occurrence from bays and estuaries was mainly from the Santa Cruz/Monterey district, where the majority of the ocean catch was also sampled, and where 54% (93,000 fish weighing 26 MT) of the estimated total catch of barred surfperch were caught (Table 12). The highest IRIs were from shore modes from the San Francisco district southward (Figures 14-16), particularly in beach/bank catches in the Santa Cruz/Monterey and San Luis Obispo districts.
Northern and central California MRFSS samplers measured approximately 11,000 surfperch from 1980 through 1986. The largest species was pile perch and the smallest was dwarf perch (Table 13). We examined the length-frequency data by species and year, and no year-class dominance was apparent. The average lengths of all species of surfperch sampled in bays and estuaries were greatest from January through June, evidence that birthing and/or breeding adults were present. In the ocean, average lengths for most surfperches were also greatest during January through June; exceptions were black perch, shiner perch, and redtail surfperch, which were longest from October through December.
Length at maturity has not been studied for many surfperches. Two of the species that were well sampled for lengths during the 1980-86 MRFSS, barred surfperch and redtail surfperch, have also been studied for length at maturity (Carlisle et al. 1960; Bennett and Wydoski 1977). Most of the barred surfperch (99.5%) sampled exceeded the minimum length at maturity of 130 mm reported by Carlisle et al. (1960) (Figure 61); the length at which 50% are mature was not reported in the study. Most (66.5%) sampled redtail surfperch exceeded 258 mm, the length at which 50% of females are mature (Bennett and Wydoski 1977) (Figure 62).
Most of the commercial surfperch catch is composed of larger species that become locally concentrated (Table 14). Adult surfperches typically aggregate during mating or birthing seasons, although barred surfperch and pile perch may form large schools year around (Feder et al. 1974). Commercial landings of redtail surfperch, walleye surfperch, and white seaperch are made primarily during the birthing season when they are concentrated inshore (Fritzsche et al. 1992; CDFG unpublished landing data). Minor landings of surfperches are made incidental to landings of other species.
The northern and central California commercial surfperch fishery is much smaller than the recreational fishery; the 1981-86 commercial landings were 54 MT (Figure 5) while recreational landings were 240 MT (Table 12). Total California commercial surfperch landings have fluctuated, but linear regression shows a decline of 25% (-22 MT) from 1953 through 1992 (Figure 63).
Gears used in commercial take of surfperch in northern and central California include hook and line, dip nets, encircling nets, and trawl nets (Figure 64). Historically, a significant portion of the catch was incidental to nearshore net fisheries. Now hook and line is the main gear used. In 1980-91 the average landing was 19.5 kg (Figure 64), or about 62 fish (assuming an average weight per fish of 0.315 kg, which is the average weight of barred surfperch and redtail surfperch sampled in the 1980-86 MRFSS). Redtail surfperch and barred surfperch comprised nearly all the landings where species were identified (Figure 65). Species were not identified in 52% of the landings, comprising 42% of the catch by weight.
The largest landings of surfperch in northern and central California in 1980-91 occurred in Crescent City and Humboldt Bay ports (Figures 1 and 66). Morro Bay and San Francisco Bay ports also had relatively large surfperch landings. Landings in Crescent City and Humboldt Bay were typically of redtail surfperch. Morro Bay landings typically consisted of barred surfperch. Of the San Francisco Bay port landings, 98% were not identified by species; of those that were, redtail surfperch, pile perch, white seaperch, shiner perch, and rainbow surfperch were common.
The commercial redtail surfperch fishery is centered in the Crescent City and Humbold Bay port areas (Del Norte/Humboldt district). Historical commercial landing statistics for those ports are summarized under the Eureka area that includes Del Norte, Humboldt, and Mendocino counties (McAllister 1976), but commercial surfperch landings from Mendocino County are negligible (CDFG data; Figure 66). The Eureka area fishery is characterized by surf netting for night smelt at night and hook-and-line fishing for surfperch by day (R. Warner, CDFG, pers. comm.). Trucks are used on beaches to haul gear and fish and for illumination of the surf while seeking night smelt. In 1980-91, average landing size in the area was 22 kg (Figure 66) or about 27 redtail surfperch of average sport size. In 1991, price paid by wholesalers in the Eureka port area was about $1.00 per pound ($2.20 per kg) (CDFG data; Figure 67). Applying that value to the Eureka area landings, the average annual ex-vessel value was $47,073 from 1980 through 1991.
Commercial landings have fluctuated, but linear regression shows a decline of 54% (-20 MT) from 1953 through 1992 in the Eureka area (Figure 68). The decline was independent of consumer demand because the price per pound grew slightly faster then the San Francisco area Consumer Price Index (CPI). After accounting for inflation, between 1953 and 1992 the price per pound increased by about $0.27 (1992 dollars) (Figure 68).
The commercial barred surfperch fishery occurs mainly in the vicinity of the ports of Cayucos and Morro Bay in San Luis Obispo County (Figure 66). Historical commercial landing statistics for those ports are included in the Santa Barbara Area that includes San Luis Obispo, Santa Barbara, and Ventura counties (McAllister 1976). The fishery is characterized by hook-and-line fishing on beaches when the fish are available nearshore (R. Hardy, CDFG, pers. comm.). Trucks are used to haul fish and gear on beaches where access is allowed. The average landing size is 12 kg (Figure 66) or about 30 barred surfperch (applying average sport sizes). In 1991, price paid by wholesalers was about $1.50 per pound ($3.30 per kg)(Figure 67). The price paid is increased by $0.05 per pound if tags are fastened to the fish. The tags allow the fish to be shipped south of Point Arguello. The average annual ex-vessel value in San Luis Obispo County from 1980-91 was $40,986.
Commercial landings have fluctuated, but linear regression shows an increase of 118% (+10 MT) from 1953 through 1992 in the Santa Barbara Area (Figure 69). The increase may be influenced by consumer demand because the price per pound has grown faster than the Los Angeles area consumer price index. After accounting for inflation, between 1953 and 1992 the price per pound increased by about $0.65 (1992 dollars) (Figure 69). Recent economic downturns may have generated increased effort and catch (R. Hardy, CDFG, pers. comm.). At Morro Bay, average annual landings of barred surfperch increased from 3630 kg ( 8002 lb.) in 1980-81 to 9070 kg (19,996 lb.) in 1990-91 (Figure 67).
Since the 1930s, the species composition of California's commercial surfperch landings has changed greatly. California's commercial surfperch fishery in 1935 was dominated by white seaperch (50%), and rubberlip surfperch (31%) (Bureau of Commercial Fisheries 1937). In 1947, the fishery was not dominated by two species but had become more diverse, including white seaperch (29%); walleye surfperch (15%); and barred surfperch, pile perch, striped seaperch and rubberlip seaperch (9% each) (Bureau of Marine Fisheries 1949). Recent data show that the fishery is now dominated by two different species, redtail surfperch (73%) and barred surfperch (23%) (Figure 65). White seaperch now comprises less than 1% of the identified commercial surfperch catch.
The species composition changes over the years appear to be related to bay and estuarine habitat use. Nearly all the formerly important commercial species (white seaperch, rubberlip surfperch, pile perch, and striped seaperch) are in the subfamily Embiotocinae and have relatively high occurrence in bays and estuaries (Figure 56). Walleye surfperch is in the subfamily Amphistichinae but also has relatively high occurrence in bays and estuaries. The two major remaining species of commercial importance, redtail surfperch and barred surfperch, are in the subfamily Amphistichinae and have relatively low occurrence in bays and estuaries. Between those two, redtail surfperch has higher occurrence in bays and estuaries and had a 25% decrease in commercial landings between 1953 and 1992. Barred surfperch has the lowest occurrence in bays and estuaries of the major species and supported a 110% increase in commercial landings between 1953 and 1992. Thus the degree of use of bays and estuaries by major surfperch species appears related to their changes in the commercial catch.
Causative factors associated with bay and estuarine use and declining catches probably include:
1) Estuarine habitat degradation caused by filling and alteration of intertidal areas, water pollution, and water diversion.
2) Overfishing of stocks relating to ease of taking fish that aggregate as part of their lifecycle.
3) Changes in commercial fishing regulations. Much of the historical surfperch catch was incidental in nearshore net fisheries directed at other species. Regulations on nearshore gillnetting and trawling have changed greatly since the 1930s. Thus changes in commercial species composition may not absolutely reflect relative abundance. For example, in recent years pile perch comprised less than 1% of the identified commercial catch (Figure 65), but comprised 18% (by weight) of the 1981-86 sport catch (Table 11).
It is difficult to determine the relative importance of the above factors. However it appears that white seaperch and rubberlip seaperch stocks underwent major declines prior to the 1958-61 survey, and that other species that make major use of bays and estuaries have declined as well. The "survivor" species in the commercial catch are the ones that use mainly open ocean habitats.
Present sport fishing regulations provide no specific restrictions for surfperch. The general finfish limitations allow a daily bag and possession limit of 10 fish of one species and 20 fish in combination of species. Permissible gears are hook and line, slurp gun, bow and arrow, and spear. For shiner perch, there are no bag or possession limits. They may be taken with dip nets of any size in all waters, with baited traps not over 3 feet in size in San Francisco Bay and in the ocean and bays of Marin, Sonoma, and Mendocino counties, and with throw nets north of Point Conception. There are no size limits or seasons for sport take of surfperch.
Presently, commercial take of surfperch is closed from May 1 through July 15, except shiner perch may be taken any time (Fish and Game Code Section 8395). South of Point Arguello, barred surfperch, redtail surfperch, and calico surfperch may not be taken (redtail surfperch are not found south of Avila). Approximately 25% of the recreational take of surfperch occurs during the time the commercial season is closed.
The commercial closure is effective, especially with barred surfperch, in reducing user conflict by allowing a period of high sport take closed to commercial harvest. However, the closure may afford little protection to female aggregations of redtail surfperch. Sixty-eight percent of bay and estuary sport catch of redtail surfperch occurs from January through April, before the commercial closure, while only 17% occurs during the closure (Figure 56), suggesting that redtail surfperch are most numerous in bays and estuaries before the closure.
Their nearshore distribution, periods of aggregation in bays and estuaries, and low fecundity make the surfperch generally vulnerable to decline. As a group, the surfperch underwent substantial decreases in sport catch, commercial catch, and in their relative contribution to the sport catch of the shore modes between the 1958-61 and 1981-86 surveys. Redtail surfperch and barred surfperch had particularly large decreases in weight landed and average weight per fish in the sport fishery. Commercial catches of redtail surfperch declined by 25% between the 1950s and the early 1990s, but commercial catch of barred surfperch increased. The decrease in commercial catch of redtail surfperch occurred despite an increase in inflation-adjusted price.
Large reductions of commercial landings of species in the subfamily Embiotocinae, including white seaperch, rubberlip seaperch, pile perch, and striped seaperch, occurred after 1935. The apparent high use of bays and estuaries by these species compared to the other surfperches may be related to catch declines, through some combination of habitat degradation, vulnerability to fisheries, and changes in fishery regulations.
A proactive approach needs to be directed at restricting or eliminating commercial harvest and to limit sport impacts. Eliminating commercial take in central and northern California would decrease the total take of surfperch by 21%. Earlier in this century, commercial take of American shad, striped bass, and white sturgeon was eliminated to conserve stocks.
Although most surfperch are taken by hook and line at this time, commercial take by alternative gears, such as nets and longline, should be eliminated. Such a change would prevent a future nonsustainable growth in commercial take if market demand should increase dramatically.
February, March, and April could be added as additional months of closure before the current commercial closure. Such a closure would add protection to redtail surfperch, pile perch, white seaperch, and striped seaperch. The closure would be most effective in bays and estuaries in protecting these species when they are aggregating for spawning and are most vulnerable to overexploitation. The closure could also be applied to the sport fishery.
The bag limit on sport-caught surfperch could be lowered from 10 to 5 fish of any one species. A total 3320 barred surfperch and 1715 redtail surfperch single-angler bags were examined (Figures 70 and 71). Ninety-eight percent of both species were sampled from bags that did not exceed the limit (10) for a single species. A five-fish limit would reduce barred surfperch by 15% and redtail surfperch by 19%. For each species only 14% of the anglers would have a reduced catch at a five-fish limit.
Minimum size requirements for selected species could be developed, based on size-at-maturity studies. Surfperch, unlike most species of rockfish, are taken from shallow water where damage from swim bladder expansion is reduced.
Harvest refugia could be established on surfperch breeding, feeding, or birthing grounds.
Research into both the ecological and human factors surrounding the surfperch fisheries should be undertaken to improve stock management. Redtail and barred surfperch, as the dominant species taken and showing evidence of decline in numbers and average weight in the sport catch, should be examined more closely. White surfperch, once historically important, should also be included.
Additional studies on the ecology of select surfperch species are needed, including reproduction, habitat selection, and energetics. Further analysis is needed of differences between surfperch subfamilies in sexual distribution during breeding season and selection of sites for parturition.
Studies of human impact on surfperch and their habitat is needed. An assessment of changes in estuarine environments that have occurred since 1960 and an attempt to quantify their effect on surfperch populations may be useful.
Research is needed on barred surfperch, redtail surfperch, and perhaps white seaperch on size at sexual maturity and timing of reproductive period. Determination of the relative success of early or late parturition may be helpful in optimizing reproductive success by timing of fishing closure months. Determination of length at which 50% are sexually mature is needed for barred and redtail surfperch in California to set size limits as a management alternative and for neonate-per-recruit modeling. Hooking mortality by length for major species is needed for setting a size limit based on catch and release survival rates as a management alternative.
The shore-based sport surfperch fishery is expensive and difficult to survey due to its seasonal and spatial patchiness. Improved MRFSS methods to estimate total effort and take of all sport fisheries are desirable. A random-based telephone expansion survey such as employed under MRFSS produces large variances. Using a sportfishing license telephone directory, as is currently being tested in Oregon (J. Witzig, NMFS, pers. comm.), could reduce variance.