MFR PAPER 1174

Monitoring the Ocean Environment

L. E. EBER

INTRODUCTION

Atmospheric and oceanographicconditions in the vicinity of the sea sur­face have historically been monitoredby mariners and fishermen. From theirobservations has come much of ourknowledge of the marine climate. Suchobservations, taken four times daily,recorded in weather logs and trans­mitted by radio to shore stations stillconstitute the primary source of infor­mation on surface conditions over theworld ocean. This information is nowsupplemented by data from weathersatellites which provide a major ad­vance in global monitoring. The ~alue ofsatellites for surveillance of atmos­pheric and oceanic conditions will in­crease greatly as sensor technology andprocessing techniques evolve.

There exists no systematic monitor­ing of subsurface conditions that can beconsidered comparable to surfacemonitoring. Subsurface temperaturesare taken with XBT (expendablebathythermograph) systems installedon U.S. Navy vessels and on selectedmerchant ships which travel regularroutes. Time-series data are providedby ocean station vessels (which arebeing withdrawn from service), and afew moored buoys and by sea-level sta­tions at coastal and island locations.Sea-level data can give an indication ofmean density in the water column in thevicinity of the station. Research vesselst~ke subsurface observations of manykmds, but at times and places pursuantto particular objectives. Such reportsmust be considered as incidental toroutine monitoring systems.

The basic purposes of monitoring themarine environment are to collectsynoptic observations adequate for in­vestigation of significant fluctuations inmomentum and heat exchange and theireffects on atmospheric and oceanic cir­culation, and on the distribution of rel­evant properties. Advances in the basicunderstanding of the ocean-atmospheresystem have application to all activitiesaffected by it, including transportation,military operations, harvesting andmanagement of natural resources, rec­reation, etc. Particular applicationsmay pose differing requirements uponthe monitoring system with respect totime and space scales and to the proper­ties monitored, although there are areasof overlap.

For many of these applications theexisting monitoring system is consid­ered inadequate. I The obvious short­comings are the lack of surface observa­tions outside normal shipping lanes andthe general deficiency of subsurface ob­servations, except along a few chosentracks. Less obvious perhaps are thedifficulties in making direct mea­surements of many important parame­ters and the uncertainties inherent incomputing heat and momentum fluxfrom existing observations. Not onlyare the semi-empirical formulas com­monly used to compute these fluxes sub­ject to question, but the actual parame­ter values used in the formulas (cloud

'The status of .oceanographic monitoring effortsa~d a .speclficatlon of needs for expansion are de·taJle~ m a recent r~po~! entitled "The ocean's rolem climate prediction, available from the OceanAffairs Board of the National Academy of Sci·ences, Washmgton, D.C.

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amount; wind speed; and sea, air anddew point temperature) are subject toobservational error. Nevertheless, inthe sociopolitical, economic, and tech­nological framework of today, there isno meaningful alternative to the existingdata collection system from ships of op­portunity (i.e., vessels whose primarymission is not collection of data) forlarge-scale moni toring of environmentalconditions.

There are, however, many ways inwhich this system can be modified andsupplemented to improve both the dis­tribution and quality of environmentalobservations. Such augmentation ofenvironmental monitoring will tend tobe selective insofar as large-scalemonitoring is supported mostly by gov­ernment agencies, and the determina­tion of where. when, and what to~onitor is guided by an agency's objec­tives or mission.

The U.S. Navy, whose ships andshore stations contribute to the basicsyst~m,. also supports supplementarymomtorIng from ships of opportunityto meet its needs for surface and sub­surface data from areas not well cov­~red by the basic system. It operatesm both a direct mode, maintaining itsown liaison with cooperating ships,a.nd als.o indirectly through coopera­tIOn With marine-oriented academicinstitutions and with other governmentagencies, including the NationalOceanic and Atmospheric Administra­tion's (NOAA) National Marine Fish­eries Service (NMFS).

Academic institutions undertake thesolution of a broad range of problemsformulated to advance understanding ofth.e ocean .and atmosphere. They con­tnbute directly to environmentalmonitoring through the activities of re­search vessels. They also contribute tothe planning and improving of monitor­ing systems through investigation ofspace and time scales relevant tosignificant processes and events, de­velopment of instrumentation andmethods of measurement suitable forlarg.e-s~ale monitoring, and through 01'­

gamzatlon of observational programsneeded to fill gaps in existing systems.

Weather satellites provide full globalcoverage of weather systems, over

L.. E. ~ber is with the SouthwestFI.shen.es Center, National MarineF/shenes Service, NOAA La JollaCA 92038. "

Figure 1.-Envlronmental data received over National Weether Service teletype circuits are recorded onpaper tape,transferred to punched cards, and Inspected for quality control. The cards are then used to updateenvironmental data tiles on disk for computer processing.

periods of about 12 hours, and partialcoverage of surface conditions depend­ing on cloud distribution. The NationalEnvironmental Satellite Service ofNOAA. which operates this system, isprimarily concerned with the sensing,reduction, and presentation of data, andhas put much effort into analysis andinterpretation of satellite data to facili­tate user application.

In general, then, agencies and institu­tions draw selectively from the con­glomerate environmental monitoringsystem according to their requirementsand contribute to the total system byimplementing subsystems, either on aunilateral or cooperative basis, to bol-

ster weaknesses in particular mission­related areas. The primary purpose ofthis review is to describe some of theactivities at the Southwest FisheriesCenter (SWFC) which fall within thatcontext. First, however, we will touchbriefly upon a few of the attributeswhich might be considered desirable inan optimum monitoring system.

THE IDEAL SYSTEM

If sociopolitical, economic, and tech­nological constraints are ignored, wecan envisage the establishment of aWorld Ocean and Atmospheric Agency(WOAA) with effective capability for

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global monitoring. The WOAA couldestablish centers for collection, reduc­tion, and analysis of all environmentaldata. The processed data could beloaded into a real-time data base acces­sible to user agencies and institutionsthrough a time-sharing network. Thereal-time data base could be updated atintervals pertinent to the events or con­ditions being monitored. Data displacedfrom the real-time data base would beadded to an historical data base in orderto update time series and long-termmeans.

User agencies could select, manipu­late, and further analyze data fromeither the real-time or historical databases and, if appropriate, store resultsback into the system to be available toother users in the network. For exam­ple, generalized weather forecasts pre­pared by a world or nationalmeteorological center might be re­trieved. through the time-sharing net­work, at some particular serviceagency's center and tailored to theneeds of that agency's constituency.

Consider the application of this con­ceptually ideal monitoring systemtoward achievement of efficient har­vesting of living marine resources andeffective resource management. Theenvironment relates to these objectivesin several ways. Thermal conditions,for example, establish the territorialrange which particular species inhabit,and therefore delineate the fishinggrounds. In temperate and colderzones, thermal conditions may havelarge seasonal variations which in­fluence migration patterns and there­fore delimit the fishing season. Devia­tions from normal environmentalconditions affect the survival (abun­dance) and migration behavior (avail­ability) of fish. Prognostic informationon long-term trends in environmentalconditions and on anomalous year-to­year fluctuations could be applied inplanning and policy decisions by pro­ducers, processors, and resource man­agers. Analyses and short-term prog­noses have application for tactical andoperational decisions.

Oceanographic analyses applicableto fishing operations might include sur­face temperature and salinity, surfacecurrents. location of surface con­vergence and divergence lines, subsur­face thermal and salinity structure, andsubsurface current structure.

Figure 2.-$88 surface temperature data applicationare edited, summarized, and plotted by computer. TheIInal analysis of Isotherms is drawn by hand. Suchmaps appear monthly in the publication FishingInformation.

For planning and management appli­cations which do not require environ­mental information on a real-time basis,analyses of oceanic properties could beprepared for time spans associated withsignificant changes in a fishery during orbetween seasons. The selection ofproperties or fields to be analyzed couldbe based on either established or poten­tial information value. Particularanalyses with wide application might beloaded into a special products data-basein the time-sharing network and madeavailable to nonagency users,fishery-related or otherwise.

Environmental research to advancebasic understandi ng of processes and todevelop applications could providefeedback into the monitoring systemthrough refinement of the specificationof time and space scales for observa­tional networks, the properties to bemeasured and the observing tech­niques.

In summary, the principal elementsof the idealized environmental informa­tion system are:

I) Capability for global monitoring ofoceanic and atmospheric properties,circulations, and energy and momen­tum fluxes on time and space scalescommensurate with significantfluctuations and events in the ocean­atmosphere system.

2) Global collection and data reduc­tion and archival facilities in which his­torical and current environmental databases would be maintained and madeaccessible to user agencies and institu­tions in a time-sharing network.

3) Partitioning of basic analysis andforecast responsibilities among useragencies according to their respectivemissions or objectives. Adaptation ofbasic outputs by other agencies tosatisfy particular constituency require­ments.

4) Global radio and satellite com­munications capability for coordinatedtransmission of environmental informa­tion products to ships at sea and remoteland stations.

5) Provision for an environmental in­formation products file in the time-

sharing system for users with require­ments for immediate access to theinformation.

6) Provision for timely preparationand dissemination by mail of time­averaged analysis and other productsnot in immediate demand.

7) Ongoing research to advance un­derstanding of basic processes in theocean-atmosphere system, to developcapability to predict anomalousfluctuations and, for fisheries manage­ment, to determine the effects on thefisheries of such fluctuations.

ENVIRONMENTALMONITORING ACTIVITIESAT THE SOUTHWESTFISHERIES CENTER

Three principal activities concernedwith contribution to and application ofenvironmental monitoring which havebeen developed at the SouthwestFisheries Center (SWFC) are: I) the

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radio facsimile (FAX) advisory pro­gram, 2) the publication of FishingInformation, and 3) the expendablebathythermograph (XBT) ship-of­opportunity program.

FAX Program

The FAX program evolved out of theneed to supplement the existing en­vironmental monitoring effort in theeastern tropical Pacific. Recognition ofthis need was stimulated by EAS­TRap AC, an international cooperativeinvestigation of the eastern tropicalPacific, which was intended to produceinformation necessary for a more effec­tive use of the marine resources of thatarea, especially tropical tunas. It wasapparent that biological and physicalproperties alike were subject tosignificant spatial and temporal varia­tions. It was also apparent that the trop­ical tuna fishing fleet afforded the bestopportunity for obtaining environmen­tal observations in the tuna habitat.

Figure 3.-0bservattons of cloud cover and weather phenomena transmitted from NOAA weather satellitescan be received directly at the Southwest Fisheries Center. Appllcallon 01 satellite data to monitor oceansurface conditions Is under development.

The NMFS's need for data from thl:eastern tropical Pacific was shared bythe U.S. Navy's Fleet NumericalWeather Central (FNWC). Environ­mental data are used by FNWC to pre­pare analyses and forecasts of oceanicand atmospheric fields in support ofU.S. Navy operations. Consequently,FNWC requires this data on a real-timebasis.

The NMFS and FNWC recognizedtheir mutual interest in enlisting thecooperation of fishermen for collectionand transmission of observational data.They also recognized both an obstaclein securing such cooperation-thatbeing a disinclination of tuna vessel cap­tains to reveal their position on thefishing grounds-and a need to providethe fishermen with some incentive totake and transmit observations. The ob­stacle was removed through innovationof an encoding scheme for transmittingdata messages which assured skippersof confidentiality with respect to theirposition. The incentive was provided inthe form of wind, weather, and sea-stateadvisory charts, prepared especially forthe area of the tropical tuna fishery andtransmitted by radio facsimile fromNMFS-licensed radio station WWD.

To implement the program, facsimile

recorders were procured from govern­ment surplus and adapted for use withshipboard communications equipment.These recorders have been installed onmore than 55 participating vessels undera reciprocal agreement providing fordaily data transmissions from the fishinggrounds. In addition, there are approx­imately 20 vessels in the program withprivately owned units. Each vessel isfurnished with its own unique encodingchart prepared at FNWC. The decod­ing keys are locked into the Navy com­puter, accessible only to the programwhich processes the observational mes­sages. All participating vessels are ex­pected to take and transmit surfaceweather observations, including windspeed and direction, weather, cloudcover, barometric pressure, air temper­ature, sea-surface temperature, swelldirection, and wave height. Some 20-25vessels in the tropical tuna fleet areequipped with XBT systems anci reportsubsurface temperatures in theBATHY message format. TheBATHY messages include tempera­tures and depths at significant pointsdown to 500 meters, extracted fromX BT analog traces. Maintenance of theXBT and FAX equipment is performedby SWFC personnel.

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In practice, tuna vessels at sea begintransmission of weather and BATHYmessages to station WWD each dayabout midafternoon. The messages arerelayed via teletype line to SWFC andaccumulated on a magnetic tape loop inthe collect and transmit terminal unit ofthe Navy Environmental Data Net­work tie-line. At scheduled times, mes­sages accumulated on the magnetic tapeare sent over the tie-line to the computerat FNWC, decoded and processed forinput to the FNWC operational pro­grams. The decoded messages, alongwith other reports from the eastern trop­ical Pacific region, are sent back overthe FNWC tie-line to SWFC and also tothe NWS forecast office at RedwoodCity, Calif.

Data originating from tuna vessels,received at SWFC from FNWC, arepunched on cards to be added to theenvironmental data base. Wind andsea-state parameters are extracted fromthese data and plotted on the currentworking charts used in preparation ofthe FAX advisories. Synoptic marinereports from merchant ships receivedover NWS meteorological teletype cir­cuits also are used for this purpose,along with analyses and forecasts re­ceived over the NWS facsimile line andthe FNWC tie-line and satellite picturesfrom NWS facsimile and from theSWFC direct readout system.

The weather advisory charts de­veloped by the FAX program at theSWFC consist of a wind and weatherforecast and a sea-state forecast. Priorto August 1974, these charts weretransmitted from station WWD dailyexcept Saturday and Sunday at about4: 15 p.m. The format and l:ontent of theSWFC FAX charts evolved throughfeedback from the fishermen. In addi­tion to forecast wind speeds and direc­tions, they depict the configuration ofthe Inter-Tropical Convergence Zone(ITCZ) and the locations of incipienttropical storms, which tend to developalong it. Such storms can intensify sud­denly and pose a hazard to tuna boatswhich tend to fish in or near the ITCZ,trying to avoid strong prevailing windsoutside but also wary of disturbancesinside.

The National Weather Service(NWS) became a participant in the pro­gram in June 1974. A data line was es­tablished from the NWS forecast office,Redwood City, Calif., to radio station

Figure 4.-Facsimlle charts sent via land line from the San Francisco Weather Service Forecast Office arereceived simultaneously at the Southwest Fisheries Center and at radio station WWD, where they arerecorded on magnetic tape. Visual Inspection Is made prior to transmission time for quality control.

WWD and to the SWFC, La Jolla,Calif., to be used for transmission ofwind and weather and sea-state forecastcharts prepared by NWS. Initially, theNWS charts were broadcast fromWWD to the tuna fleet on weekends, tofill the gap in the SWFC transmissions,and recorded weekdays at the SWFCfor evaluation and assessment of com­patibility in format and in depiction ofsignificant forecast elements.

Since August 1974, the NWS FAXcharts have been broadcast from WWDdaily. Surveillance of wind and weatherconditions in the eastern tropical Pacifichas been continued at SWFC, however,to insure that supplementary verbal ad­visories are broadcast from stationWWD when appropriate, and to re­sponu to direct requests from tuna ves­sels for information in specific situa­tions.

[n addition to the daily wind,weather, and sea state FAX advisories,three charts depicting ocean conditionsare prepared at SWFC and transmittedby radio facsimile weekly. These are asea-surface temperature analysis, amixed layer depth analysis, and a sea­surface temperature difference chartwhich compares present conditionswith those in the corresponding week ofthe previous year.

The success of the FAX program de­pends on continuing participation of alarge number of tuna vessel ownersand captains. The importance of takingobservations, encoding them properly,and transmitting the radio messagesmust be stressed repeatedly. On theother hand, dialogue with the fishermenis also necessary to modify and adaptthe advisory products as nearly as pos­sible to their needs.

The weather logs and X BT recordskept aboard the tuna vessels are col­lected by SWFC personnel when thevessels return to San Diego. Data takenon the fishing grounds but not receivedthrough the real-time transmission sys­tem are extracted from the logs andadded to the environmental data base.

Fishing InformationCharts of sea-surface temperature

(SST) for the eastern north Pacific werepublished by the Honolulu LaboratoryofNMFS (then the Bureau of Commer­cial Fisheries, BCF) from 1957 through1959 in connection with a study of thedistribution of north Pacific albacore.

Responsibility for preparation of thecharts was assumed by the BCF TunaForecasting Program, San Diego, Calif.in 1960, in order to provide up-to-dateSST information to the tuna fishing in­dustry. governmental fishery agencies,marine scientists, and meteorologists(Johnson, Flittner, and Cline, 1965).This program also undertook the compi­lation and publication of historical SSTdata back to 1947, in furtherance ofstudies on tuna environment (Johnson,1961; Renner, 1963).

Initially, the SST charts were issuedmonthly for the region north oflat. 200 Nand east of long. 180° and, during thealbacore fishing season. semimonthlyfor the region oflat. 25° to 52°N and eastof long. 136°W. Monthly SST plots forI-degree squares were prepared for theeastern tropical Pacific between lat. 20°Nand 200 S. The computation of themonthly and semimonthly mean tem­perature values, and the plotting ofthese values on base maps for analysesof the temperature fields, were doneby hand. As emphasis shifted to auto-

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matic data processing and feedbackfrom users identified additional needsfor environmental information, theanalyses were extended to include otherregions and other properties.

Fishing Jnformation now containsthe following monthly charts: a) Seasurface temperature for the easternnorth Pacific; b) Sea surface tempera­ture for the western north Pacific; c) Seasurface temperature for the easterntropical Pacific; d) Deviations fromlong-term means of a), b), and c); e)Difference between a) and the corre­sponding SST field one year earlier; f)Sea level pressure and resultant wind(both current month and long-termmonthly means) for the eastern northPacific.

Fishing Jnformation also containsgraphs of subsurface temperature struc­ture along ships' routes from Hawaii toU.S. west coast ports, narrative de­scriptions of the significant features ofthe charts, and articles on the albacorefishery at the beginning and end of thealbacore fishing season.

The semimonthly SST charts are nowpublished year-round as the Fishing In­formation supplement. During the al­bacore fishing season, they are accom­panied by the A Ibacore Bulletin whichcontains timely information on fishingconditions and on the progress of thefishery.

I n addition to the charts listed above,a set of tabulations is produced eachmonth which contains average SST's,air temperatures. dew point tempera­tures, sea level pressures, cloudamounts, and resultant winds for5-degree squan:s. From these monthlyaverages of observed environmentalvariables are computed the principalcomponents of heat exchange at the seasurface, including incoming radiation,reflection, back-radiation, evaporation,

Figure 5.-Advlsory charts prepared lor radio fac­simile transmission are displayed for convenient ref­erence along with environmental charts and satellitepictures received from the Nallonal Weather Service,and Fleet Numerical Weather Central.

and sensible heat flux. The tabulationsalso contain deviations of each of theobserved and computed variables fromtheir respective long-term monthlymeans. These monthly tabulations arenot routinely distributed, but are avail­able for on-site use by local users. Also,a preliminary run of the 5-degreeaverages is made a few days before theend of each month for use by the LongRange Prediction Group of the Na­tional Weather Service. Cooperationwith other organizations in this way of­fers potential benefit through progressin understanding and prediction oflarge-scale environmental fluctuations.

The computation of heat exchangecomponents from monthly averages ofobserved environmental variables givesrelatively gross estimates of heat fluxacross the sea surface. Although therehave been attempts to use such esti­mates in oceanic heat budget studies,their value for monitoring significant

fluctuations has not been fullyevaluated. To make the informationmore widely available, an I I-year series(1961-1971) of total monthly heat ex­change has been compiled in chart formfor the eastern north Pacific, and pub­lished along with monthly mean chartsof each of the principal componentsaveraged over the same period (Clarket aI., 1974).

The principal source of data for theenvironmental charts prepared by theSWFC, other than reports from tunavessels, are the 6-hourly synoptic ship'sweather observations transmitted fromships at sea in the International Ship'sMeteorological Code and collected byNWS. The system developed by theTuna Forecasting Program in 1960 forprocessing the observations employed acomputer program which producedprinted SST summaries and otherparameters at the end of each month.The summary values were hand plotted

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and analyzed to prepare the environ­mental charts for Fishing Information.The original observations were savedon punched cards.

Subsequently. programs were addedor modified to produce new outputssuch as digital plots to replace thoseformerly done by hand, and specialprintouts formatted in a geographicalgrid for convenient reference. The pres­ent system provides for frequent up­date and ready accessibility of both cur­rent and past data on disk and magnetictape files so that operational programscan be run on schedule and specialanalyses or plots for any time period andany specified region can be run as re­quired.

Ship-of-Opportunity Program

This program was initiated to expe­dite utilization of a new instrument sys­tem (the XBT) capable of augmentingsubsurface temperature monitoring andto apply the new system to create timeseries of subsurface temperature dataalong well-frequented shipping routes(Saur and Stevens, 1972). Such data areneeded for the identification, quantita­tive description, and understanding ofseasonal and nonseasonal changes inthe subsurface temperature structureand heat content and of mass transports(through geostrophic estimation of cur­rents) in the upper layers of the tropicaland northeast Pacific Ocean. The pro­gram activities comprise three phases:I) Data collection. in which observa­tions of surface salinity and of verticaltemperature profiles are made at

120-170 km intervals with expendablebathythermograph instrumentationaboard ships of opportunity; 2) Dataprocessing, in which the observationsare digitized, edited, printed for conve­nient reference, and added to the XBTdata base for research; and 3) Dataanalysis. in which temperature-depthsections are prepared and the observa­tions are analyzed to depict changes insubsurface ocean conditions.

The ship-of-opportunity programstarted in 1966 with a single ship, theMatson Navigation Company's bulksugar carrier Californian, which madeabout two trips per month on the SanFrancisco-Hawaii run. The presentprogram is considerably larger and, in1974, involved three shipping com­panies and nine different ships. t Duringthat year the program produced 52 sec­tions between San Francisco andHawaii, 27 sections between LosAngeles and Hawaii, 10 sections be­tween Seattle and Hawaii, 2 sectionsbetween Alaska and Hawaii, 4 sectionsbetween Tahiti and Hawaii, and 4 sec­tions between Samoa and Hawaii.

The program is conducted jointlywith the N MFS Pacific EnvironmentalGroup, Monterey, Calif., where thedigitization and computer analysis ofsubsurface temperature structures isperformed and through which liaisonwith cooperating ships is supervised.Responsibility for the data analysis was

'Matson Navigation Company. Chevron ShippingCompany. and Pacific Far East Line. Mention oftrade names. commercial products, or firms doesnot imply endorsement by the National MarineFisheries Service, NOAA.

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Figure 5.-Weather advisory charts can be receiveddally by fishing vessels such as this one equipped withradio facsimile recorders. Observational data receivedfrom the fishing vessels contribute significantly to theaccuracy of the advisories.

transferred from SWFC to the ScrippsInstitution of Oceanography (projectNO RPAX) at the end of 1974. The pro­gram interfaces with FNWC interests inglobal monitoring of subsurface tem­perature on a real-time basis and withacademic interests in understanding theprocesses of air-sea interaction andfluctuations in oceanic heat storage.The program receives support fromFNWC, in the form of computer timeand expendable probes, and from theNational Science Foundation and theOffice of Naval Research through pro­ject funding.

FNWC has supported the installationof X BT systems on merchant, fishing,and research vessels to supplementthose on naval ships in order to obtainbroad geographical coverage with sam­pling intervals sufficient to resolvelarge-scale oceanic features. Fordefinition of mesoscale eddies, whichhave come under recent investigationby oceanographers and may be impor­tant in connection with transient oceanfronts, much finer sampling is required.Such sampling can be carried out frommerchant ships only when project ob­servers are aboard. The N MFS pro­gram has endeavored to maintain an in­termediate sampling interval sufficientto identify transition zone characteris­tics between water masses and to revealsignificant fluctuations along repeatedtracks.

Figure 7.-Some fishing vessels are equipped with expendable bathythermograph systems. Temperature­sensing probes, released from a hand-held launcher. send data back to the vessel through fine conductorwires as they descend through the water.

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Ancillary Information Sources

In establishing capability for monitor­ing environmental conditions of con­cern to fisheries, SWFC has become anacquisition center for real-time en­vironmental information in a variety offorms. Analyses and forecasts of sub­surface. surface, and upper air condi­tions are received daily over the FNWCtie-line and plotted as charts on Cal­Comp plotters. A similar array of prod­ucts is received over the NWS fac­simile circuit. The NWS circuit alsocarries gridded satellite pictures frompolar-orbiting and geostationaryweather satellites. These pictures areparticularly useful in determining thelocation and configuration of the ITCZand in following the development oftropical storms. SWFC also can receivepictures transmitted directly from the

polar-orbiting satellites on nearby orbitswhich occur twice each day. The satel­lite pictures, oceanographic andmeteorological analyses, and forecastcharts are displayed on the chart boardin the: environmental data room for con­venient reference by environmentalanalysts, other SWFC staff, and vis­itors. The daily proximity of current en­vironmental charts helps the analyst be­come attuned to the time and spacescales of real-time events and developinsights which can lead to new ap­proaches in the investigation of theocean-atmosphere system.

Weather satellites have great poten­tial for ocean monitoring, and the Na­tional Environmental Satellite Servicehas spent considerable effort in the in­terpretation of data from scanningradiometer infrared sensors to deter­mine sea-surface temperatures. AI-

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though significant problems exist, oneof the foremost being cloud contamina­tion, this effort appears certain to leadto useful application, and growing con­sideration has been give to ways of in­corporating this information into theroutine SST analyses. The SWFC hascooperated with the Inter-AmericanTropical Tuna Commission, throughuse of the direct readout satellite receiv­ing system, in studies to evaluate thefeasibility of using data from scanningradiometer sensors aboard NOAAsatellites to discern oceanic fronts andto apply satellite data to problems offishery oceanography (Stevenson andMiller, 1974).

APPLICATION TO FISHERIES

The purposes underlying SWFC'sinvolvement in environmental monitor­ing, through the programs described inthe preceding section, are to contributeto the development of the real-timefishery prediction capability and effec­tive resource management. A fisheryprediction and management systemshould accomplish two basic functions:I) Help maintain the fishery at a level ofabundance consistent with optimumyield and recoverability from adverseenvironmental conditions or excessivefishing pressure; and 2) Increase theefficiency of harvesting, through predic­tion of distribution and availability, inorder to maintain a viable fishery thatcan deliver fishery products to the con­sumer at an economical and competitiveprice. By strengthening the total en­vironmental monitoring effort in areaswhich are important to fisheries, the po­tential benefit of research in relation­ships between the environment andfisheries is enhanced.

Environmental data taken by tropicaltuna fishermen on the fishing grounds inthe eastern tropical Pacific during1971-1974, as a direct result of the FAXprogram, are shown in Table I. Thesedata are being utilized in ongoing re­search on the relationship between en­vironmental parameters and fishingsuccess.

The FAX program contributes to theefficiency of harvesting by meeting theneeds of tropical tuna fishermen for in­formation on weather and ocean condi­tions. Interviews with 22 skippers andnavigators were conducted betweenDecember 1973 and March 1974 to ob­tain the fishermen's evaluation of the

MFR Paper 1174. From Marine Fisheries Review, Vol. 38, No.2, February1976. Copies of Ihis paper, in limited numbers, are available from 0825,Technical Information Division. Environmental Science InformationCenter, NOAA, Washington, DC 20235. Copies of Marine Fisheries Revieware available from Ihe Superintendent of Documents, U.S. GovernmentPrinting Office. Washington, DC 20402 for $1.10 each.

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The last category includesmeteorologists, military oceanog­raphers, marine suppliers, librarians,trade journal publishers, and others.The survey revealed that the charts areused primarily for fishing strategy bycommercial and sport fishermen, forplanning by processors, for fishery re­search by fishery managers, and for en­vironmental research and teaching bymarine scientists, meteorologists, andeducators. The survey indicatedgreatest interest in the SST charts forthe eastern north Pacific; however, allof the environmental charts receivedfavorable response.

Overall, the response to the ques­tionnaire affirms that the program is ac­complishing its original objectives. Itbenefits the industry by providing usefulenvironmental information and contrib­utes to potential advances in fisheryprediction by benefiting environmental

charts are copied by about a dozen ves­sels equipped with FAX recorders byAFRF. As with the tropical charts,they provide the fisherman with en­vironmental information applicable tofishing strategy. and also support thework of the albacore investigations inmodeling the albacore fishery.

The series of monthly andsemimonthly charts of sea surfacetemperature and other environmentalfields, published in Fishing Informationand its Supplemenl. go back as far as1960. They are sent to a distribution listof some 1,196 individuals, organiza­tions, institutions, and agencies, someof whom receive copies for further dis­tribution. In order to assess the impactand utilization of these charts, recip­ients were asked to fill out and return abrief questionnaire distributed with theNovember 1973 issue. A total of 575questionnaires were returned. They re­veal the following breakdown by userclassification:

Table 1.-Summary of marine observations,1971-1974.

TotalYear Weather BATHY observations Boats

Collected by radio station WWO

1971 '844 684 1.528 3-251972 2.150 498 2.648 39-531973 2,579 570 3,149 55-571974 2.178 408 2,586 61-63

Total 7,751 2.160 9,911

Collected from weather and BATHY logs

1971 ---' 886 ---' 3-251972 2.610 665 3.275 39-531973 5.167 1,160 6.237 55-57

'1974 3.265 616 3.881 61-63

Total 11,042 3.327 14,369

lWWD did not collect weather observations on a regularbasis until September of 19712Weather observations from fishing vessels were inte­grated into the monthly deck of synoptic observationsand not separately accounted for.31974 figures are based on projections pending receiptof all of the 1974 data.

FAX products. Nearly all of those in­terviewed indicated that they copied theFAX charts every day, if possible, andlistened to the verbal advisories broad­cast on weekends when severe wind orweather conditions were expected.

The information regarded as mostvaluable is the location and expectedmovements of chubascos (tropicalstorms) and of extreme wind conditionssuch as occur in the Gulf of Tehuan­tepec. Sea and swell advisories and thesea surface temperature charts wererated next in value for aid in decidingwhen and where to fish. The mixedlayer depth charts are being copied bymost of the vessels, judging from thesample response, but were given a highvalue rating in only a few cases. Thesecharts represent an effort to furnish en­vironmental information to thefisherman on a provisional basis andthereby enlist his participation in de­veloping the potential application ofsuch information to fishing strategy.The charts also form a time series de­picting weekly changes in oceano­graphic features. which may induceshort-term variations in fish behaviorand distribution.

The FAX program also provides aservice to the albacore fishery throughweekly transmission of sea surfacetemperature charts covering the alba­core fishing grounds. This activity con­tributes to the joint research effort of theSWFC Albacore Research Investiga­tion and the American Fishermen's Re­search Foundation (AFRF). These

User classification

Commercial fishermenProcessors and distributorsSport fishermenFishery managersMarine scientistsTeachersOther

Percent oftotal returns

3839

10161014

and fishery research. It should be notedthat the preparation and distribution ofenvironmental charts by this program isa unique undertaking, and to some de­gree, provides the only generally avail­able source of quasi-current informa­tion on abnormal conditions, such as EINino occurrences. The SWFC receivesnumerous inquIrIes during suchanomalous events concerning the statusand tendency of environmental condi­tions.

Although much work has been doneon the relation of fish to environmentalconditions, the problem has hardly beenscratched. An intensive and long-rangeresearch effort must be sustained to de­termine the specific extent and nature ofenvironmental control on the distribu­tion, survival, and behavior of fish. Asimilar effort must be made to under­stand the forces that produce environ­mental fluctuations which may havesignificant effects on a population. Suchefforts must be supported by a com­prehensive monitoring of the ocean­atmosphere environment and by reli­able assessments of sizes and locationsof populations. Only when adequate de­scriptions of relevant environmentalfields are available along with adequatedescriptions of fish stock distribution,can the knowledge of environmentalprocesses and of behavioral responsesto such processes be applied effectivelyin a fishery prediction system to controlthe fishery.

LITERATURE CITEDClark. N. E.. L. Eber. R. M. Laurs. J. A. Renner,

and J. F. T. Saur. 1974. Heat exchange betweenocean and atmosphere in the eastern northPacific for 1%1-71. U.S. Dep. Commer..NOAA Tech. Rep. NMFS SSRF-682. 108 p.

Johnson. J. H. 1961. Sea surface temperaturemonthly average and anomaly charts north­eastern Pacific Ocean. 1947-58. U.S. Fish Wildl.Serv .. Spec. Sci. Rep. Fish. 385.56 p.

Johnson. J. H .. G. A. Flittner. and M. W. Cline.1965. Automatic data processing program formarine synoptic radio weather reports. U.S.Fish Wildl. Serv.. Spec. Sci. Rep. Fish. 503,74 p.

Renner, J. A. 1963. Sea surface temperaturemonthly average and anomaly charts easterntropical Pacific Ocean. 1947-58. U.S. Fish Wildl.Serv., Spec. Sci. Rep. Fish. 442. 57 p.

Sauro J. F. T .. and P. D. Stevens. 1972. Expend­able bathythermograph observations from shipsof opportunity. Mar. Weather Log 16( I): 1-8.

Stevenson. M. R.. and F. R. Miller. 1974. Applica­tion of sate IIi Ie data to study oceanic fronts in theeastern Pacific. Inter-Am. Trop. Tuna Comm ..S.P.O.c. Final Rep. Grant No. 04-3-158-59.III p.