Relationships of Fish Yield to Lake Phytoplankton Standing Crop, Production, and Morphoedaphic Factors

Abstract

Oclesnv, R. T. 1977. Relationships offish yield to lake phytoplankton standing crop, production, and morphoedaphic factors. J. Fish. Res. Board Can. 34:2271-22'79.Fish yield is related to annual pfimary production, summer phytoplankton standing crop, and the morphoedaphic index for lakes representing a wide variety oftypologies by a series of models in the form of 1og-log regressions. Tentative boundary conditions are established by which lakes inappropriate to the models can be excluded. Confidence intervals for predicted values about the mean are given for the fish yield-phytoplankton standing crop regression. From this relation, potential yields for the lakes studied are reduced from a range of 10,000 to one of 25-fold. Efficiencies with which carbon is transferred from primary production to fish yield vary by 2Io3 orders of magnitude and are highest for small, intensively managed ponds and lowest for large, deep, cold-water lakes. Models based upon fish yicld as a function of phytoplankton production or standing crop are inherently more accurate and subject to fewer exceptions than are those related to morphoedaphic factors. The former appear to be capable of substantial refinement but even in their present state might be employed to make useful predictions for groups of lakes. A suggested supplement to existing approaches in fishery management involves the following sequence: (1) use ofexpectation-variability diagrams to obtain an overview ofthe problem, (2) selection ofan appropriate model or models to predict yield, (3) prediction ofa range ofyields, and (4) implementation ofregulations proved successful for other lakes in the same yield category.

Relationship between Lake‐Record Weights of Fishes and Reservoir Area and Growing Season

“…Such analyses commonly are limited by the quality and quantity of information available on physical and biological characteristics of the study waters. For example, Oglesby (1977) found that nutrient concentrations were better predictors of fish yield than were morphoedaphic characteristics such as mean depth and surface area. Nevertheless, our results show that this approach can provide general insight into mechanisms affecting the production of trophy fish.…”

Kajian Kualitas Air Dan Potensi Produksi Sumber Daya Ikan Di Danau Towuti, Sulawesi Selatan

“…Produktivitas primer sebagai parameter biologis telah digunakan dalam pendugaan potensi produksi ikan di danau oleh Oglesby (1977);Melack (1976) dalam Kartamihardja (1987). Besarnya potensi produksi ikan di Danau Towuti yang diukur di enam stasiun penelitian pada waktu survei pertama berkisar antara 2,403-10,182 kg/ha/tahun dengan nilai ratarata 5,467 kg/ha/tahun.…”

Association of turbidity and organic carbon with bacterial abundance and cell size in a large, turbid, tropical lake

“…The annual catch is high relative to the low quantity of phytoplankton production. For example, Oglesby's (1977) model, which uses primary production to estimate fishery yield, predicts a fishery only two-thirds of that realized. In other tropical lakes having a fishery comparable to that of Lake Chapala, primary production is almost an order of magnitude greater.…”