were made with rotenone (about 1 qt Noxfish 2 ) at 

 low tide in August, except in 1983 and 1985, when 

 they were made in July and in 1984 when they were 

 made in September. Specimens were taken by dip 

 net from the pools by my students and me An at- 

 tempt was made to collect and then count and 

 measure (mm SL) all fishes. Sometimes I used a face 

 mask to find fishes at the bottom of the pool which 

 was closer to the ocean. Many invertebrates also 

 were killed, but no attempt was made to record num- 

 bers. The most abundant invertebrates in the 1984 

 collection were the green crab, Carcinus maenas 

 (Linnaeus), and the sea urchin, Strongylocentrotus 

 droebachiensis (Miiller). Also collected were amphi- 

 pods, Gammarellus angulosus (Rathke), Calliopius 

 laeviusculus (Kroyer), and Gammarus oceanicus 

 Segerstrale; isopods, Idotea baltica (Pallas); and scale 

 worms, Harmothoe imbricata (Linnaeus). 



Results 



Thirteen species of fishes were collected (Table 1). 

 The number of species per collection varied from 3 

 to 8 (x 5.3). One species, the rock gunnel, Pholis gun- 

 nellus (Linnaeus), was collected in all 22 samples. 

 Young cunner, Tautogolabrus adspersus (Walbaum), 

 were found in all but two collections. The grubby, 

 Myoxocephalus aenaeus (Mitchill), and the threespine 

 stickleback, Gasterosteus aculeatus Linnaeus, were 

 present in 17 and 15 collections, respectively. The 

 radiated shanny, Ulvaria subbifurcata (Storer), was 

 taken 12 times. The seasnail, Liparis atlanticus (Jor- 

 dan and Evermann), was taken in 10 collections, the 

 mummichog, Fundulus heteroclitus Linnaeus, in 8. 

 The American eel, Anguilla rostrata (LeSueur), was 

 taken four times; young lumpfish, Cyclpterus lum- 

 pus Linnaeus, three times. Four of the 13 species 

 were taken only once or twice: the Atlantic tomcod, 

 Microgadus tomcod (Walbaum); Atlantic silverside, 

 Menidia menidia (Linnaeus); ninespine stickleback, 

 Pungitius pungitius (Linnaeus); and northern 

 pipefish, Syngnathus fuscus Storer. I can detect no 

 long-term change in species composition or number 

 of individuals over the 19-yr period. 



The number of specimens per sample varied from 

 17 to 1,850 (x 197.5), but the mean is distorted by 

 the 1,842 young (9-28 mm SL) Tautogolabrus adsper- 

 sus taken in sample 16. Deleting this number, the 

 figures are 17-343 (x 119.2). Thus, a "typical" sam- 

 ple would consist of 41 Pholis gunnellus, 49 young 

 Tautogolabrus adspersus, 12 Myoxocephalus aenaeus, 



2 Reference to trade names does not imply endorsement by the 

 National Marine Fisheries Service, NOAA. 



7 Gasterosteus aculeatus, and 2 Fundulus 

 heteroclitus. One other species might be present, 1 

 or 2 specimens of any of the other 8 species, most 

 likely Ulvaria subbifurcata or Liparis atlanticus. 

 There is great variation from collection to collec- 

 tion in numbers of specimens of the most abundant 

 4 species: 2-232 Pholis gunnellus; 2-1,842 Tauto- 

 golabrus adspersus; 1-127 Myoxocephalus aenaeus; 

 and 1-44 Gasterosteus aculeatus. Ulvaria subbifur- 

 cata, Liparus atlanticus, Cyclopterus lumpus, and 

 Fundulus heteroclitus showed much less variation, 

 1-12 per collection. The other 5 species were uncom- 

 mon, numbering 1-4 specimens. 



Discussion 



To evaluate short-term effects, comparisons can 

 be made between pairs of collections made in 1969, 

 1982, and 1983 at 2-3 wk intervals. The number of 

 species decreased from 8 to 6 in the 1969 pair and 

 from 7 to 5 in 1982, but the number increased from 



3 to 5 in 1983. Four of the 8 species in the first sam- 

 ple in 1969, and 3 of the 7 species in the first sam- 

 ple in 1982, numbered only 1 or 2 specimens, as did 

 one of the species in the second sample of 1983. 

 Numbers of individuals were about the same in the 

 1969 pair of collections (over 50) and the 1983 pair 

 (74 and 86), but decreased (54 to 17) in the second 

 collection of the 1982 pair. Rapid recolonization of 

 the tidepools clearly takes place. Differences in thor- 

 oughness of collecting, plus apparent random varia- 

 tion in the 7 least commonly taken species, can 

 explain the few differences between the paired 

 collections. 



Thomson and Lehner (1976) sampled a large tide- 

 pool in the Gulf of California 11 times over the period 

 1966-73. The period of time between sampling 

 ranged from 13 to 78 wk. Number of species ranged 

 from 16 to 26, total 50; number of individuals 435- 

 2,627, total 11,701. No decrease in number of species 

 or individuals over time is apparent from their data 

 (Thomson and Lehner 1970:table 1). 



Grossman (1982) sampled a series of rocky tide- 

 pools with quinaldine at Dillon Beach in northern 

 California 15 times from January 1979 to May 1981. 

 The period of time between sampling ranged from 



4 to 21 wk. Number of species per sample varied 

 from 9 to 18 (excluding the first sample, 12-18), total 

 29 species; number of individuals was 71-517 per 

 sample [not 520 as in Grossman's (1982) table 3], 

 total 2,853 individuals. The structure of this rocky 

 intertidal fish taxocene was persistent over 29 mo 

 through 15 defaunations (Grossman 1982:table 3). 



Beckley (1985) sampled three South African pools 



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