Interagency Ecological Studies Program for-the Sacramento-San Joaquin Estuary LIBRARY COPT - NEWSLEITER BAY-DELTA FISHERY PR~::~;1994

Readers are encouraged to submit brief articles or ideas for articles. Correspondence, including requests for changes in the mailing list, should be addressed to Randy Brown, California Department of Water Resources, 3251 S Street, Sacramento, CA 95816-7017.

EDITOR'SNOTE:Thefollowing article was submitted by Dr. Bruce Herbold of the U.S.Environmental Protection Agency. The author describes the data and rationale he used to arrive at estuarine habitat standards to protect . Written comments on this or other articles In the Newsletter are welcome and will be presented, along with the author's responses, in the spring edition. -R. Brown and P. Herrgesell Habitat Requirements of Delta Smelt Bruc,z Herbold, USEPA One of the greatest difficulties in question is: "Does the occurrence springs (Sweetnam and Stevens devising protection for the threat- and duration of suitable habitat 1993). ened delta smelt has been to deter- during the spawning and nursery When delta smelt are in Suisun mine exactly what is threatening period in spring relate to subse- Bay, they are found in greatest them. In their recent Biological quent delta smelt adult fall abun- abundance at stations in the shal- Assessment, DWR and USBR dance?" pointed out the lack ofa significant lows (Moyle et al 1992). It is un- relationship between delta smelt Delta smelt are found in greatest clear whether this greater capture abundance and a wide array of abundance at salinities near 2 ppt rate reflects a habitat preference of variables. The absence of a simple (3.0 mS/cm). During the recent smelt or greater efficiency of the linear relationship with any of the drought almost the entire popula- sampling gear. environmental factors associated tion was found near Emmaton (Figure 1), where bottom salinity with flow results from delta smelt's Methods apparent low abundance in years stayed near 2 ppt almost year- of either very low or very high flow round. By contrast, in 1993 about The quantity of shallow, low- half the population remained in conditions (Moyleet al1992; Moyle salinity habitat available each year and Herbold 1989.) The following throughout the sum- was estimated by calculating the analysis focuses on the habitat re- mer, although the region of 2 ppt number ofdays between February 1 quirements ofyoung delta smelt as retreated upstream. This is consis- and June 30 when salinities of2 ppt low salinity water in or near shal- tent with the pattern in' earlier were in Suisun Bay. The numbers low habitat (Moyle et al1992). The years when dispersal of delta of days were calculated based on smelt was greater fO'llowingwetter the fall is significant at the 0.05 level (r=0.496). Figure 2 is a scatter plot of the data, with each point labeled by year. The driest year on record (1977) and the wettest year on re- cord (1983) both provided no days of2 ppt in Suisun Bay and resulted in low abundances of delta smelt. 'Ibtal delta outflows were similar in 1986 and 1993, but the single large storm in 1986 did not provide as much habitat, or as many delta smelt, as the more prolonged pre- cipitation of 1993. The early 19708 yielded successive years ofvery high delta smelt abundance despite pro- ducing as few as 60 days of2 ppt in Suisun Bay. 'Ib identify which areas in Suisun Bay contributed mostto the overall relationship, I calculated a sepa- rate correlation for each 5-lan reach of the delta smelt historical range ( to Rio Vista). The number of days when 2 ppt was in FlQUre 1 each 5-km reach was correlated SACRAMENTO-SAN JOAQUIN DELTA with the subsequent abundance of delta smelt. The resulting Pearson outflow (QOUT from the DAY- Results and Discussion correlation coefficients are shown FLOW data set) and the X2 equa- in Figure 3, labeled by a shore tion described in Kimmerer and The correlation between the num- location near the upstream end of Monismith (1993); ie, ber of days from February through each reach. The correlation for the June when mean daily salinities of X2t=10.16+0.945·X2~.1t1.48rLog,o(00UT}t reach from to Middle 2 ppt were in Suisun Bay and the Ground is significant at the 0.01 These calculated values have been abundance of adult delta smelt in level. It is the only signific;:ant shown to accurately reflect meas- ured salinities in and near Suisun Bay (Kimmerer and Monismith 2000 T I a. 1993). The calculated values pro- u 70. .80 vide a continuous data set, unlike Cca '0 the salinity data, which contain c 1500 :::J many gaps and do not include data ,Q 0« 72. for all stations in all years. For 73• •• 1993, a preliminary estimate ofthe "i 1000 Delta Outflow Index was obtained E rn from DWR. Springtime conditions CD 81. .8a in each year from 1967 to 1993 •• "i ~7 were compared with subsequent Q 500 87. a8 .•2. • a1 abundance of delta smelt as meas- - '8 88. 87 • 'i • a8 I&. 82. .84 ured by DFG's fall midwater trawl '.a aa. survey (excluding 1974 and 1979, 0 I I which were not sampled). Data used 0 50 100 in this analysis are available from the author. Number of Feb-Jun Days with 2 ppt In Suisun Bay FIQure2 SPRING HABITAT EFFECTS ON DELTA SMELT RECRUITMENT value (:r=0.558).Note that all values ~ downstream of c CD or upstream of are U .•.;: negative, while all sites in Suisun CD o Bay are positive. o c Th try to pinpoint the months of o ;: greatest sensitivity in this relation- III ship, I calculated a separate corre- 'i.. o.. lation for each month of the year. o The number of days when 2 ppt c was in Suisun Bay for each month ..~ -0.2 ofthe water year preceding the fall III CD midwater trawl was correlated a. with the subsequent abundance of "0:'\OO\.~,,\t't'S\lE.,,C~i\~"~••10~,~\\..E.'oI\S1" delta smelt. The Pearson correla- ••• co"f'o,; s.,... E.~ ,,\0 tion coefficients for each month are FIgUre 3 displayed in Figure 4. Correlations CORRELATIONS WITH 5-KM REACHES from October through May are high but only the peak in April ••c represents significance at the 0.05 CD level (:r=0.486). U 0.4 .•.;: However, within a year, the auto- CD o 0.3 correlations in time and space re- o duce the reliability of any analysis ~ 0.2 that compares parts of years or ;; II small geographic areas. ! 0.1 o.. o 0.0 Conclusions c o The resurgence of delta smelt in f! -0.1 II CD 1993 to the highest abundance in Q. 13 years, after a 12-year period of record low abundance, suggests stock/recruitment relationships FIQure4 play a small role in determining CORRELA nONS IN EACH MONTH the fall abundance of delta smelt. The higher captures of delta smelt ability of suitable habitat limits However, spring of 1993 provided near waters of2 ppt and in shallow the abundance of this species. In more of the habitat this species habitats (when waters of2 ppt are the absence of a significant stock! appears to require than any other near shallow habitats) strongly recruitment relationship or tie to year on record. The recent high suggest habitat selection·by delta any other environmental variable, abundance of delta smelt is consis- smelt. The tie between the amount availability ofnursery habitat seems tent with the pattern in earlier of this habitat and fall abundance to be the primary limiting factor to years when springtime conditions of delta smelt argues that avail- abundance of adult delta smelt. in Suisun Bay correlate well with fall abundance. References There is some evidence that a large Kimmerer, W, and S Monismith. 1993. An estimate of the historical position of 2 ppt part of this relationship rests on salinity in the Estuary. in Managing Freshwater Discharge to the San Francisco Bay/Sacramento-San Joaquin Delta Estuary: The Scientific the number of days in April when Basis for an Estuarine Standard. San Francisco Estuary Project. salinities of 2 ppt are between Moyle, PB, B Herbold, DE Stevens, LW Miller. 1992. Life history and status of the delta Middle Ground and Roe Island. smelt, Hypornesustranspacificus, in the Sacramento-San Joaquin Estuary, Califor- However, for 1993, larval smelt nia. Trans Am Fish Soc 121:67-77. were reported as early as February Moyle, PB, and B Herbold. 1989. Status of the Delta Smelt, H:Jl1X21lKSUS transpacificus. and as late as June, so nursery Final Report to US Fish and Wildlife Service. 19 pp + app. habitat may be needed throughout Sweetnam, DA, and DE Stevens. 1993. Report to the Fish and Game Commission: A the 5-month period. Status RelJiewof Delta SmeU (lbpomesus transpacificus) in California. Candidate Species Status Report 93-DS. Potamocorbula Amurensis Survey Peggy Lehman, DWR, and Wayne Fields, Hydrozoology Introduction of the Asian clam Po- data were based on natural geog- where densities reached only 9,578 tamocorbula amurensis (Mollusca raphy. Hymanson (1991) described clamslm2. Densities near 9,578 Corbulidae) in the San Francisco the methods in detail. clamslm2 were also measured in Bay/Delta estuary in 1986 has . In Suisun Bay, den- been of great concern because of its sities were comparatively low; high grazing rate (Hollibaugh and maximum density for a single sta- Werner 1991) and an associated Distribution of P. amurensis was tion was 4,981 clamslm2 in Grizzly decrease in cWorophyll biomass similar during 1990 and 1993. Bay and 1,245 clamslm2 in Honker and production rate in Suisun Bay During 1990, clams were almost Bay. Few were found upstream of (Alpine and Cloern 1992). Suisun always found from the southern Honker Bay. Maximum density Bay is of concern because it often end of San Pablo Bay eastward measured for one station was 2,644 serves as a nursery for many estu- into the delta. For the Sacramento clamslm2 at Chipps Island. Densi- arine species. Clam larvae were River, clams were found upstream ties remained below 2,107 clamsIm2 probably introduced from ship to just below Horseshoe Bend (sta- in the Sacramento and San Joaquin ballast water (Carlton et a11990), tion 145). For the San Joaquin rivers. and adult clams were first detected River, clams were found as far up- There were large differences be- in 1986. During the 1987-1992 stream as Jersey Point (station tween years in the number of P. drought, the clam spread through- 172). During 1993, upstream dis- amurensis in each Ponar sample out much of the estuary and was tribution increased slightly. Clams for most regions. For San Pablo common in the Suisun Bay region were found about 1.5 km farther (Lehman 1994, in press). Bay, the number of clams increased upstream in the by a factor of9, from 3,033 in 1990 'lb determine the extent ofP. amu- on the other side of Horseshoe to 27,936 in 1993 (Figure 2). For rensis and the influence of fresh- Bend (station 146), and in the San Suisun Bay and Suisun Marsh, the water flow on its distribution, two Joaquin River 1.5 km farther up- number of clams decreased by a surveys were conducted. The first stream from Jersey Point (station factor of3 to 5 in 1993. Numbers of was in late August and early Sep- 173). clams sampled in the delta region tember 1990 (Hymanson 1991), a In 1993, most P. amurensis were remained stable. critically dry year; the second was found in San Pablo Bay. Densities Changes in numbers of clams sam- in late August and September 1993, 2 up to 43,000 clamslm were meas- pled were accompanied by differ- the first subsequent wet year. ured at station 19, in the southern ences in size distribution. For San The following summary describes end of the bay (Figure 1). Maxi- Pablo Bay, most P. amurensis in some ofthe initial fmdings for 1993 mum density at each station was 1990 were 14 mm long or less, and and makes some comparisons with at least four times lower in the most of these were 12-14 mm long the 1990 survey. A more compre- northern end of San Pablo Bay, (Figure 2). By 1993, most of the hensive description and analysis of the data are in progress. 45000 T 4OO0Oס Methods Single benthic samples were col- lected from about 190 stations throughout the bay and delta using C'l j!25OOO a Ponar dredge (0.052 m2). Sam- c; pling stations were 2 km apart in ~ 20000 the shoals and 1.5 km apart in the 15000 channels (any region narrower than 2 km). In addition, stations in the channels were alternately sampled near the bank and the center of the channel. For each station, density and size distribution ofP. amuren- 1 11 21 31 41 51 81 71 III 111 101 111 121 131 141 151 161 171 161 1111 sis and substrate type were deter- STATION mined. Regional divisions of the FIgUre 1 ClAM ABUNDANCE IN 1993 Page 4 clams were less than 10 mm long and most of these were 2-5 mm I SAN PABlO BAY 1993 1 long. For the rest of the estuary, I 25 clam size was larger in 1993 than n-27936 1 § ;; lj in 1990 (Figure 2). In 1990, most of I ~ ~~l 10 the clams were less than 13.5 mm 15 ~ 10 db ••. 5 for Suisun Bay shoal and channel : ~IIIII.... ~I.~__ o ~I~I.~.~------o 2 4 6 8 101214161820222426 o 2 4 6 8 101214161820222426 stations and less than 7 mm for lENGTH mm LENGTH mm Suisun Marsh and the delta. By ~ 1993, clams were usually larger than 8 mm throughout the bay, marsh, and delta, and maximum 25 •.. 20 density occurred between 11 mm e 15lLuu and 16mm. I E 1~ _I_II~I_••~.~.~. _ I~I..•.. IIII1ttJJJ~ •.'-- _ o Summary L 0 2 4 6 8 ::~4~ 18 20 22 24 26 P. amurensis were slightly farther upstream in 1993 than in 1990. Clam densities in 1993 were 25 25 higher in San Pablo Bay, lower in 20 1 n-739 SuisUn Bay and Suisun Marsh, j :~ and similar in the delta than in 5 o 11...... • _..__ 1990. Size distribution shifted o 2 4 6 8 10121416 182022 24 26 o 2 4 6 8 101214161820 22 24 26 from clams less than 13 mm in lENGTH nom lENGTH mm 1990 to clams greater than 10 mm in 1993, except for San Pablo Bay. For San Pablo Bay, the population n-186 shifted to small clams about 2-5 r ~~i mmlong.

~ 30~ f 20 i I '~ ~I.~.~ _ I W_••__ 0 2 4 6 8 1012 14 16 18 20 22 2426 ~Io 2 4 6 8 1012 14 16 18 20 22 24 26 I I lENGTH nom

Figure 2 CLAM SIZES, 1990 AND 1993

Literature Cited Alpine, AE, and JE Cloern. 1992. Trophic interactions and direct physical effects control phytoplankton biomass and production in an estuary. Limrwl Ocearwgr 37:946-955. Carlton, JT. 1985. Transoceanic and interoceanic dispersal of coastal marine organisms: the biology of ballast water. Ocean Mar BioI Ann Rev 23:313-371. Hollibaugh, JT, and I Werner. 1991. Potamocorbula Amurensis: Comparison of Clearance Rates and Assimilation Efficiencies for Phytoplankton and Bacterioplankton. Interagency Ecological Study Program, Technical Report 29. Hymanson, ZP. 1991. Results ofa SpatiaUy Intensive Survey for PotamocorbulaAmurensis in the Upper San Francisco Bay Estuary. Interagency Ecological Studies Program for the Sacramento-San Joaquin Estuary, Technical Report 30. Lehman, PW. 1994. Water Quality Conditions in the Sacramento-San Joaquin Delta During 1992. Environmental Services Office. Department of Water Resources (in press). 1993 Georgiana Acoustic Behavioral Barrier Evaluation Charles H. Hanson, Hanson Environmental, Inc. Juvenile Chinook salmon emigrat- delta channels, impede upstream given to evaluating the guidance ing from the upper Sacramento migration ofadult fish, and obstruct efficiency of behavioral barriers River and its tributaries are sus- recreational boating. An alterna- and also the potential for increased ceptible to diversion into the cen- tive approach would be a behav- susceptibility to predation losses, tral delta at the Delta Cross ioral barrier designed to utilize the sublethal physiological effects, Channel, Georgiana Slough, and avoidance response of juvenile potential delays or blockage in adult .Threemile Slough. Studies using salmon to reduce diversion into upstream migration, and other fall-run salmon smolts have dem- Georgiana Slough without ad- factors that influence the overall onstrated substantially higher versely affecting hydrology, flood biological benefit associated with mortality rates for those fish pass- protection, water quality, or navi- behavioral barrier operations. ing into the interior delta. The gation. The San Luis and Delta-Mendota increased mortality rates reflect, Behavioral barriers have had vari- Water Authority, in cooperation in part, increased susceptibility to able success in reducing losses of with the State Water Contractors, predation, delays in migration, fish at water diversions. Factors DWR, and USBR, initiated a exposure to increased water tem- research project in 1993 to test the peratures, and increased suscepti- contributing to the variable results include differential response to a effectiveness of an underwater bility to entrainment losses at the stimulus between species and life acoustic repulsion system (barrier) SWP and CVP and a large number stages offish, environmental conm- in deflecting fall-run Chinook of other water diversions in the tions such as streamflow and tur- salmon smolts from entering Geor- delta. Juvenile winter-run Chinook bidity, and diversion hydraulics. giana Slough at its confluence with losses as a result of entrainment at the Sacramento River (Figure 1). the SWP and CVP diversions are In several recent applications where The acoustic array used species- regulated by incidental take provi- a behavioral b~erwas targeted on specific sound frequencies targeted sions of the Endangered Species the avoidance response of a specific to Chinook salmon smolts. The Act. The allowable level ofinciden- species, a substantial increase in studies were coordinated through tal take has been established as 1% effectiveness was demonstrated. the Interagency Program's Fish of the estimated number ofwinter- However, additional consideration Facilities Committee. run smolts entering the delta. If and scientific evaluation need to be effective in deterring a portion of juvenile Chinook salmon from entering the interior delta through Georgiana Slough, use of an acous- tic (underwater sound) behavioral barrier could contribute to an in- crease in survival of all races of salmon during emigration. The successful guidance of winter-run Chinook from entering Georgiana Slough would also contribute to a reduction in their susceptibility to entrainment losses at the SWP and CVP diversions and, therefore, a reduction in incidental take as a result ofwater diversion operations. Proposals have been considered to physically block passage of juve- nile salmon into Georgiana Slough by installing a rock barrier or other structures. Concern has been ex- pressed, however, that a physical barrier in Georgiana Slough may FlQUre 1 adversely affect water quality, alter LOCATION AND CONAGURATION OF ACOUSTIC BARRIER IN THE SACRAMENTO RNER the natural flow of water from the UPSTREAM OF GEORGIANA SLOUGH DURING FINAL WEEK OF PHASE I AELD TEST Sacramento River through interior (BaHd 0/1 twiaI photographs taken June 11, 1993) Page 6 Objectives of the 1993 field inves- toward the mid-channel area ofthe sive documentation on environ- tigation were: Sacramento River a sufficient dis- mental conditions such as velocity, tance upstream of the confluence flow rates, and acoustic signal • Install and operate an acoustic with Georgiana Slough to allow mapping and more replication to array upstream of Georgiana guidance and passage down- allow statistical testing for differ- Slough on the Sacramento River. stream. The barrier was sub- ences in juvenile Chinook salmon • Document the effectiveness of sequently modified each week catch-per-unit-effort in Georgiana the acoustic barrier in reducing based on results of the biological Slough and the Sacramento River the numbers ofjuvenile fall-run evaluation. Results of the evalu- as a function of acoustic barrier Chinook salmon smolts entering ation (Figure 2) show a pattern of operations. The 1994 research pro- Georgiana Slough. increasing guidance efficiencydur- gram includes a number of inde- ing each weekly testing sequence. pendent measures of acoustic 'Ib evaluate the effectiveness ofthe The final two testing sequences barrier efficiency to help evaluate acoustic barrier, we determined (June 1 and 4, June 7 and 10) had barrier performance given the changes in the ratio ofjuvenile fall- an estimated index of guidance relatively high degree of variabil- run Chinook salmon captured in efficiency above 50%. ity in Kodiak trawl catch-per-unit- Georgiana Slough and the Sacra- effort observed during the 1993 The 1993 field test results were mento River during periods when studies. In addition, the 1994 stud- encouraging but did not provide the acoustic barrier was on and ies will document changes in the during periods when it was off. the necessary degree ofreplication horizontal and vertical distribu- to support rigorous statistical tion ofjuvenile Chinook salmon in Results of fish collections, per- analysis, calculation of absolute fonned using a Kodiak trawl, were response to acoustic barrier opera- guidance efficiency that can be tions, using both trawling and reported as a catch-per-unit-effort used with confidence to represent to account for variation in sam- hydroacoustic monitoring and a range of environmental condi- coded-wire tag mark/recapture pling effort. A total of 610 Kodiak tions, or detailed analyses on trawls were completed in Georgiana studies to estimate survival rates changes in the distribution pattern for juvenile Chinook salmon dur- Slough and the Sacramento River of juvenile Chinook salmon in between May 6 and June 10 for use ing periods when the acoustic bar- response to acoustic barrier opera- rier is on and periods when it is off. in evaluating effectiveness of the tions. Therefore, additional inves- acoustic barrier. Juvenile Chinook Although each of these alternative tigations have been designed for approaches has inherent strengths salmon comprised 95% (5,163 1994 to provide more comprehen- salmon) of the total number offish and weaknesses for use in evaluat- collected (5,460 fish). ing acoustic barrier perfonnance, ~ collective results of the 1994 tests Results of the first complete weekly j ,: should provide a sufficient basis testing cycle (May 10-14) showed a .1 •• for evaluating guidance efficiency greater relative number (ratio) of J" of the acoustic barrier for juvenile ~" juvenile Chinook salmon entering y , Chinook salmon smolts. l •• Georgiana Slough when the acous- ii ... tic barrier was on compared to .. The 1994 studies will also consider, ].. . through various field and labora- catches when the acoustic barrier j . was off, resulting in a negative in- tory experiments, effects of the dex of guidance efficiency (Figure acoustic signal on hatching success 2). We hypothesized that the angle and survival of larval and juvenile and location ofthe acoustic barrier fish, increased susceptibility to were too close to the entrance to predation, and potential changes Georgiana Slough given the chan- in resident fish populations in nel hydraulics, resulting in insuffi- response to acoustic barrier opera- cient reaction time and distance tions. Radio tagging and hydro- for juvenile Chinook salmon to re- acoustic surveys are also proposed spond to the barrier and overcome to evaluate the potential for block- velocities of water entering the age or delays in adult upstream slough. Based on this hypothesis, Figure 2 migration ofadult striped bass and RATIO ESTIMATES AND the configuration of the acoustic fall-run Chinook salmon as a direct INDEX OF GUIDANCE EFFICIENCY result ofacoustic barrier operations. barrier was modified in an attempt OF THE ACOUSTIC BARRIER to guide juvenile Chinook salmon (Bas6d on Chinook salmon catch per 1,000 rrt' sampled in KodaIctllWls iIthe ~ RAw 8IId ~ SbJ{1J.) ·Development of Striped Bass mM Nears Completion Jim Cowan, University of South Alabama & Kenny Rose, Oak Ridge National Laboratory In a thoughtful contribution to the fishes (for more information, see weight, age (d), life stage, and Autumn 1993 edition of the Inter- papers from an IBM symposium other attributes are chronicled for agency Newsletter, Wun Kimmerer published in Volume 122, Number each individual. Egg and yolk-sac identified several information 3 in Transactions of the American larval development and mortality needs relative to forthcoming man- Fisheries Society). Models of fish rates are expressed as a function of agement decisions about the delta. populations dynamics, if process daily temperature. Upon initiation Specifically, he suggested that oriented, can enhance our ecologi- of fIrSt feeding, initial weight and "new conceptual models and popu- cal insights about how populations length of feeding larvae in each lation models for the estuary that function within their environment. female cohort are determined from can be coupled with the developing Because growth and mortality in egg weight. Feeding larvae develop hydrodynamic models"... (were fishes is related and because fishes into juveniles when their length needed) to try to predict what has have highly plastic and variable exceeds 20 mm. and will happen there to many bay/ growth rates within classes or co- When larvae begin to feed, they are delta fishes. For the last 3 years, horts, the mechanisms governing followed day-by-day through researchers at the Oak Ridge survival and recruitment (and growth and mortality processes. National Laboratory, in collabora- ultimately evolution) operate at Larvae are sampled from each co- tion with scientists from the DFG the level of the individual. When hort in proportion to that cohort's Bay-Delta Fishery Project, DWR, individuals differ substan~ially, contribution to the total number of Interagency Program, and the aca- the results we see at the popula- surviving first-feeding larvae. demic community have been devel- tion level may be derived from a Daily growth of each individual oping an IBM (individual-based small minority of atypical indi- beginning at fIrSt feeding is calcu- model) of the striped bass popula- viduals. Thus, models based on the lated via a bioenergetics relation- tion in the delta. The model has average individual are likely to ship. Aml\ior departure from other been developed as part of a larger provide little insight into the fac- bioenergetics approaches, how- project designed to study compen- tors that affect recruitment vari- ever, the proportion (P) of maxi- satory mechanisms (COMPMECH) ability and often are misleading. mum consumption realized by an in fish population dynamics. The I thi 1· ht th Cali£'.' d 1 individual on a given day here is S SJ 'R' n s Ig ,e lorma mo e acramento-. an oaqUln"egms Iver b'Wl ·th spawnmg . b' y m di Vl 'd - determined from stochastic prey stnped bass, populatIon ,IS on~ of ual females and simulates the encounters with multiple zooplimk.- f~ur populatIOns under mvestiga- growth and mortality of the newly ton prey groups for feeding larvae tlOn by ~OMPME?H, whose spawned striped bass as they de- and multiple benthic prey groups l~ger gOall~ to make mt,erpopula- velop through the egg, yolk-sac lar- for juveniles. t~on ~ompansons of s~nped bass val, feeding larval, juvenile, and life ~stor~ a~ros~ envu:onmental adult life history stages, The young- Mortality of feeding larvae and gradients mdicatlve of Its range, f th d 1 ts th juveniles depends on weight and " 0 - e-year mo e represen ese length. Weight-dependent mortal- With the mcorporation. of new data dyn am'lCS d'l' 81 Y m m ult'Ip Ie, we 11 - and fine tumng based on resul~ of mixed compartments that repre- ity is considered to be due to star- a recent ~orkshop, a ~rst yerslon sent different regions within the vation. Length-dependentmortality of a full-life-cycle Califorma ffiM is estimated from field data and, soon Wl·11 be comp1 eted an d will estuary . 1 (eg, upper SacramentoRi therefore, includes predation and ·d rful to 1 £ d . RIver, ower Sacramento ver, p~OVl e a powe o. or ~Cl- lower , Suisun other losses. Probability of dying slon-makers charged ~th sorting Bay). Environmental conditions con- (PcJJ is evaluated daily for individu- M out the complex envl~onment~l sidered in each compartment are als: Pd - (l-e- ), for which M = C?nsequences of the -mIsmatch m daily water temperature, fraction 0.003 + 0.295 * e.Q·07S"'L. (We are tune and place ~~ween water sup- of the 24-hour day with daylight, attempting to define a separate ply an~ demand m the d~lta. The and the densities of zooplankton mortality curve for each compart- foll.oWlng paragraphs bnefly de- and benthic prey types. ment.) If the generated random scnbe the ffiM approach and our number from a uniform distribu- plans to use the model to address For the egg and yolk-sac stages, tion between 0 and 1 is less than some issues we and our collabora- each female's spawn of eggs is Pd. the individual is assumed to tors deem most important. followed as an entity (cohort); a die. Thus, growth rate (size) is .,. . random sample of individuals is directly tied to mortality rate in IBMs ,are recelvmg mcreasmg followed for the feeding larval and simulations. attentIon as a means of under-, ·1 h · d . f Juvem e stages. Total lengt , standi ng pop ul at Ion ynamlcs 0 PageS After the fIrSt year of life, ffiM Our first simulations will attempt nutritional condition will be re- output on numbers and mean to address the following types of moved based on appropriate em- length of age-1 survivors combined questions: pirical data from the simulated from all compartments of the YOY population in one or more of the How do different flow regimes module are used as input to a

90 . DISPATCHER REPORT INFLOW - UPPER 80 ~ U 4 ~\ OUTFLOW - LOWER 870 a Q60~ XSO C/) -9-40 ~30 0 u: 20 10

0 - JAN MAR MAY JUL SEP NOV

r"'a §, 10 ~ DISPA TCHER REPORT L L SWP PUMPING x 8 C/) -0 6 '-' Q) 4 Z Cl: 2 2 ~ 0 JAN MAR MAY JUL SEP NOV

r"'a §,10 ~ DISPATCHER REPORT CVP PUMPING x 8 C/) -0 6 '-' Q) 4 Z Q.. 2 ~ ~ 0 JAN MAR MAY JUL SEP NOV 1992-1993 I Page 10 Bay Fisheries Data Report Chuck Armor, DFG The Delta Outflow/San Francisco fisheries data to include the recent Preparation of this report has Bay Study has completed a draft drought years. Included are a com- helped focus staff biologists on report that describes the basic life pilation of the catch and percent what we know and what we don't histories and summarizes catch by gear type and year for all know. It has also provided fresh 19801992 abundance, distribu- species offish, shrimp, and Cancer insights into the biologyofthe spe- tion, salinity, and temperature crabs; the Secchi disk data; and the cies included and mechanisms that data for 28 species offish, 4 species surface and bottom salinity and may control their abundance and of shrimp, and Dungeness crabs. temperature data collected by the distribution in the estuary. During The report is being reviewed and study. For fIsh and crabs, informa- the preparation, many questions will be published either as part of tion is presented for young-of-the- arose about various species, and DFG's Fishery Bulletin series or as year and where possible 1+ (one these will questions will provide an Interagency Technical Report. year and older) individuals. For the basis for future investigations shrimp, information was broken and publications. Preparation of this document has down by mature and immature in- been an ongoing effort interrupted This report is a departure from dividuals as well as by sex and egg by water right hearings, staff past reports prepared by the study maturity stage. Data that were not changes, and other demands for in that it concentrates on basic bi- analyzed for this report but that staff time, such as analysis used ology and data summarization will be included in future efforts for endangered species review. The rather than on the effects of out- include larval fish catch -and final document will be over 400 flow. length frequency and larval pages and is the first comprehen- shrimp and crab data. sive review of San Francisco Bay

Annual Workshop

::::i:ii The Interagency Program annual workshop will be held March 2-4 at

:i·i·!.! :~:~~~~~; f~~:~:~~g~:~;:~::tsp~~:;~~v:fi;::e:f:~:,~r: \:t: the Interagency Program is being revised to cope with these issues. It should be a stimulating meeting. These people have more information: Chuck Armor, DFG ~ : 209/948-7800 Jim Arthur, USBR 976/978-4923

Marty Kjelson, USFWS " . , 'l' , •••• 209/946-6400 Pete Smith, USGS...... 976/978-4648 (Ext 373) JimSuffon,SWRCB 976/657-2790 11:::~::mlti:m:%t~i:'~:::::;~:';:;ll~:::::~;t;~::i~~lm~:1__ W_;~~::S-7~ INTERAGENCY ECOLOGICAL STUDIES PROGRAM ANNUAL WORKSHOP March 2-4, 1994 AsilomarConference Center

March 2 - Wednesday

1:00 Anive and Assemble - DO NOT check inl 1:30 Welcome and Announcements ...... Jim Arthur. USBR

INTERAGENCY ECOLOGICAL STUDIES PROGRAM REPORTS 1:40 The Revised Interagency Ecological Study Program: - OveIView of the Revised Program - Staff Level Management Team - Project Work Teams - Science Advisory Group - Management Advisory Group...... Perry Herrgesell. DFG

PROJECT UPDATES • • • • . . • • ...... • • • Chalr: Pete Smith. USGS 2:20 Georgiana Slough Acoustic Barner...... Chuck Hanson. Hanson Environmental Inc. 2:45 Status of the Suisun Marsh WOdlife Program ...... Steve Cordes. DFG and Brenda Grewell.DWR 3: 10 Estuarine Food Chain Conceptual Models ...... Wim Kimmerer. BioSystems Analysis Inc. 3:45 CHECK IN - Pick Up Keys to Rooms 6:00 Dinner - SeIVed Only UntO 7:00 PM 7:00 Social Activity and Guest Speaker: Exotic Species in the SF Bay Estuary...... Jim Carlton/Andy Cohen (Tentative) 8:30 Adjourn

7:30 Breakfast 8:15 Announcements...... Chuck Armor. DFG

ENDANGERED SPECIES . . • ...... Chair: Marty KJelson, USFWS 8:25 1992/93 Winter Run Field SUIVey Results ...... Mark Pierce. USFWS 8:50 Winter Run Recovery Team Activities: Jim Smith. USFWS - What has the team been doing? - What constitutes recovery? - What actions are needed to recover? 9:15 1992/93 Delta Smelt Field SUIVey Results Dale Sweetnam. DFG 9:40 Delta Smelt Biological Opinion...... Cay Goude. USFWS 10:05 Break 10:30 Delta Native Fishes Recovery Team Actlvlties:...... Peter Moyle. UCD - What has the team been dOing? - What constitutes recovery? - What actions are needed to recover? Sacramento SplittaO Field SUIVey Results Randy Baxter. DFG/ Lesa Meng. USFWS

CVP IMPROVEMENT ACT • . . . . • • . • • • . • • ChaIr: Jim Arthur. USSR 11:20 OveIView with Emphasis on the Bay/Delta Estuary ...... Jim McKevitt/Roger Guinee. USFWS 11:45 The Doubling Plan - How Will It Be Done? ...... Terry M1lls. DFG 12:10 Lunch 1:00 Free Time 5:00 Social Hour - Drinks and Snacks 6:00 Dinner

EVENING SESSION: THE EPA STANDARDS ••.•••••.•••••• Chair: Leo Wlntemltz, DWR 7:00 Policy Behind the Estuarine Standards: - Why they were developed? - How they will be implemented? - How long they will be in effect? - What is their relationship to BDOC? - Results of the Public Hearing...... Patrick Wright, USEPA 7:20 Biological Basis for X2 and EPA Standards Bruce Herbold, USEPA 7:45 The Hydrodynamic Element - New Insights/New Questions ...... Jon Burau, USGS 8:10 The California Urban Water Agencies Biological Team- New Perspectives? /New Solutions? Jud Monroe/Randy Bailey. CUWA 8:35 The State Response - How W1l1the State Make New Standards Work? Jeny Johns 8:55 Questions and Discussions ...... All 9:30 Adjourn

March 4 - Friday

TECHNICAL SESSIONS. , •••• '•.•••• , .• Chair: Chuck Armor, DFG 8: 15 New National Marine Fisheries SeIVice Screening Policy and New Screen Technologies - Modular Inclined Screens...... Danyl Hayes/Ted Frink, DWR 8:40 Results of the 1993 Clifton Court Forebay Predation Study ...... Jennifer Bull/Mike Healy. DFG 9:05 Response of Sturgeon, Bass and Other Fish to 1993 Hydrologic Conditions...... Lee M1ller/Dave Kohlhorst, DFG 9:30 Break 9:55 Response of Potamocorbula (Asian Clam) to 1993 Hydrologic Conditions ..... Peggy Lehman, DWR

OUTSIDE TOPICS •...•.•.•.•.••. , .. Chair: Jim Sutton, SWRCB 10:20 Suspended Solids Concentrations in Central San Francisco Bay During the 1993 Winter Runoff : ...... Dave Schoellhamer, USGS 10:45 Delta Wetlands Project. Jordan Lang, Jones & Stokes 11: 10 Check Out of Rooms 12:00 Lunch 1:00 End of Workshop

A POSTER SESSION will be held concurrently with the Workshop. Please review the contributions dUring breaks or during other times. (A list of posters is on the next page).

NOTE: Unless otherwise indicated, speakers w1llbe allotted 25 minutes. Presentations should be 15 minutes and there should be 10 minutes left for questions.

TIME LIMITS WIIL BE STRICTLY ENFORCED Timer: Jim Obe Enforcer) Sutton - Pheasant Hunt - SuIfPerch - PacificHerring - Geographicallnfonnation System - Agncultuial DiversIonStudy - What Is A Winter Run? - Egg and Larval Automatic Sampltng - Data AcquisItion for the NewCompUanceMonttonng Program - StIiped Bass Spawning on the Sacramento River - Fishery Improvements at Red Bluff - Delta SOS

Interagency Ecological Studies Program NEWSLETTER 3251 S Street Sacramento. CA 95816-7017

Interagency Ecological Studies Prcgram for the Sacramento-San Joaquin Estuary NEWSLETTER A CooperatlveEffort of: California Department of Water Resources California Department of Fish and Game State Water Resources Control Board U.S. Fish and Wildlife Service u.S. Bureau of Reclamation U.S. Geological Survey U.S. Army Corps of Engineers U.S. Environmental Protection Agency

Editors: Randy Brown, Department of Water Resources Perry Herrgesell. Department of Fish and Game Vera Tharp, Department of Water Resources