FISHERIES OCEANOGRAPHY WARREN S. WOOSTER ’ Scripps Institution of Oceanography University of California, La Jolla, California In considering how to summarize the oceanographic stirring aiid cmistal np~~~lling)or secontlary effects aspects of the papers we have just heard, I found of thr wind-driven circulation (for exaniple, doming my thoughts falling into several distinct rategories- or ridging). the definition and goals of fisheries oceanography, cur- The near surface circulation may aff~ctdirectly rent practice in this field, adthe success of this the distribution or abundance of organisms at all approach. trophic lcvc~ls. In addition, changes in the intensity Some may feel that fisheries oceanography is noth- of the refertilizing procc’sst’s are reflected in the time ing more spwific than the broad assemblage of prob- mid spaw distribution of primary produc:tioii. This lems being studied by oceanographers working for in turii affects production iii thr n~xthig1ic.r trophic fishery laboratories. The interests of marine fisheries level, aiid so on. with assorted time and spac:e lags, scieiitists and those of oceanographers overlap in SO to the desircd fish. At each step ill this line of rwson- maiiy arras that aliiiost any marine rc>search can be iiig, rrfinmnieiits and eoniplications are involvrtl, but, inclnded in a suitably broad definition. But unfor- the basic thciiie of the model reinaiiis: tniiately \uch broad definitions haw little opera- ii (’haiiges in the wind firld lcacl eve~ltually to tional value. changes in the succ(~ssof fishing. ’’ One might speak, however, of a somewhat restricted Th(3 goal of investigatioii of this niotlel is often roil- area of marine research which could be calld ecologi- siderrd to be prdictioii. Crrtainly if one could fore- (.a1 oceanography. This deals with the relationship cast awurately the c~hang(~siii ahiiiidaiwe, tlistribrition between the ocean as a physico-chemical environment atid availability of fish, this \wnld be of great eco- and the populations of organisms inhabiting it. A nomic significance. Riit, concc~ivably, a useful prp- special case exists in which the populations consist of diction coiild result from the blind statistical treat- species of commercial intmest. This point of view meiit of a large Iinniber of variables, rather than from lrads to tlie following definition : a fundanirntal iintl(.r.staiitliiig of the iiitclrplay of the Fishcries Orea7iograpliy-the study of oceanic proc- pertinent atiiiospheric, oceanic, aiicl biospheric proc- esses affecting the abundance and availability of esses. It is the acquisition of this fiuitlanieiital knowl- commercial fishes. edge which is the scieutific goal of fisheries oceanog- Obviously populations of comniercial fishes are af- raphy. fected by other than oceaiiic processes. In particular C‘iirrc.iit prartice in fisheries owanography has coii- they are subject to the pressure of an aggressive noii- centrated on clociuneiitiiig and trying to intcrprcJt the eiiviroiiriieiital factor, the fisherman. Much of fisheries changes in the iiiariiie environment. One of tlic lcad(~rs research has resulted from the fear that this pressure in this field in the 1Tiiitcd States was the late Town- was excessive and ~vouldsoon lead to decimation of send Croniw.11, who originall>- proposed this syin- the stock ; thus it has concentrated primarily on the posium. His first iniportaiit work, iii Honolulii, JYBS a dyiianiics of the populations involved. The working study of wiiid-induc.ec1 upwelling aloiig the quator. hypothesis of the fisheries oceanographer, oil the other Subseyiwntly, the IIonolnlii group has examined the hand, is that variations in apparent abundance are mechanisms of surface enrichnicwt near the Hawaiian due primarily to changes in the cnvironnient. These Tslands aiid to the north. At Scripps Institiition and changes niiist bc described aiid understood before the the Tnna Cornmission, thcre have been st,iitlies of role of man can be propcrly evaluated. cwastal upwelling, oceanic2 froiits, ant1 of processw The relationship is traced out in a model which such as those Crom\wll labelled “doming” or iiridg- starts with the observation that sigiiific~ant c1iangc.s ing ”. Dr. Sette and his c*olleagiies have bwn exaniin- in the atmospheric pressure field ocmr from place iiig past weather and the riiariiie climate, looking for to place and from time to time. These ehanges lead long-term changes related to those in the fisheries. 1111 to variations in thc stress applied to the sea surface of these iiivestigations have been facilitated by the by the wind. It is now generally believed that the presence of certaiii cdoiispiciions featurcs or disconti- major near-surface circnlation of the oc~aiiis wind nuities. As Henry Stoinniel has suggested, studying drivrn, so that the changing \tilid stresy caiises the oceans resembles diswcting a lobster-if is easier changes in the velocity, depth, breadth, transport or to do at the joints. other characteristics of tlie surfacr cwrrciits. Further- That has been the success of fishery oceanography more, tlie processes whereby the surface layw is refer- in recent years? Certainly in the Pacific it has had no tilized with nutrient elements from below appear to dramatic impact 011 the cornniercial fish(4es. L\iitl if be either directly mind-prodnced (for example, wind the goal be considered prediction, very little SII(T~SS 1 Contribution from the Scripps Institution of Oceanography can be recorded. Yet the fund of basic knowledge of 74 CALIFORSIB COOPERATIVE OCEXKIC FISHERIES ISVESTIGATIOSS the ocean has increased tremendously. The near sur- other important surface-enriching mechanisms are face circulation and the distributions of properties known. In short, the general scheme by which atmos- such as temperature, salt aiid oxygen have been much phere, ocean and biosphere are interrelated is taking more adequately described. The theory of wind-driven form, and we are ready to formulate aiid test hypoth- circulatioii is well established. The variations in time eses having bearing on important and specific prob- and space of coastal upwelling are recognized, and lems in fisheries science. .