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The availability of fresh and frozen fish in the urban and rural areas

Kukułowicz A., Klawikowska M.

Zeszyty Naukowe Akademii Morskiej w Gdyni

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2015

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nr 89

29--34

EN

Eating fish is an indispensable element of a proper and well balanced diet. Despite the benefits of consuming fish, their consumption in Poland is still at a low level. At present, buying fresh fish in the urban areas is not much of a problem for consumers, because they can be purchased in fish stores, as well as in large commercial networks or at marketplaces. The aim of the study was to compare the consumers’ opinions on the availability of fresh and frozen fish in urban areas and in rural areas of Wejherowo district. The study was conducted with the use of a questionnaire survey in the group of 180 not randomly chosen people. According to respondents’ opinions on the availability of fish it appears that urban areas of Wejherowo district are characterized by high availability and a wide range of fresh and frozen fish, while rural areas have limited access to those products.

2

Towards the optimal foraging strategy : is seasonal shift in the diet of Cormorants Phalacrocorax carbo (L.) in a dam reservoir the effect of water temperature or size pattern in fish assemblages?

Gwiazda R., Amirowicz A.

Polish Journal of Ecology

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2010

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Vol. 58, nr 4

783-792

EN

According to optimal foraging theory the prey choice strongly affects the benefitcost ratios. Predators search prey giving the highest benefit and costs of all components of predation (i.e. prey search, encounter, pursuit, capture, and handling) may be considerably reduced if the prey is more available. The study on Cormorant diet and the species composition of prey fish assemblages in the Dobczyce Reservoir (area 985 ha, submontane, eutrophic reservoir in Southern Poland) in spring (May-June) and in autumn (Oct-Nov) showed differences in the food composition and the prey size affected by seasonal changes in fish availability. The diet of Cormorant included eleven fish species and the dominant species in the food was roach in spring (72%) and roach and perch in autumn (49% in total). Roach and perch had the highest share in prey assemblages too (56% in spring, and 53% in autumn). Significant preference toward roach in spring was found. The share of roach and perch did not changed seas seasonally and could not explain the change in the composition of Cormorant diet. The range of the total length (LT) of fish in Cormorant diet was 3.5-35.2 cm. Diet consisted of distinctly smaller fish in autumn. Relative number of small fish was ca 3 times greater in this period compared to spring. Weighted mean of fish TL in prey assemblage was 20.0 cm for roach and 12.5 cm for perch in spring, and 11.8 and 8.1 in autumn, respectively. The proportion of average weight of roach (W = 0.004074 LT[^3.334]) to that of perch (W = 0.005779 LT[^3.260]) was greater in spring (4.1:1) than in autumn (2.9:1). Probably it can explain the diet shift in autumn. The switch to smaller but more abundant fish in autumn was not related to temperature but to fish availability which reduced the cost of searching and the prey may be easily found.

3

Can poor foraging habitat (an inundated opencast sulphur mine) be attractive to the great crested grebe (Podiceps cristatus)?

Gwiazda R.

Oceanological and Hydrobiological Studies

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2009

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Vol. 38, No.3

135-139

EN

During investigations of an inundated opencast sulphur mine (an open, deep water habitat with a relatively small littoral area) only five species of breeding water birds were recorded. The density of breeding great crested grebes Podiceps cristatus was relatively high (c. 1.0-1.1 pairs 10 ha-1 of water, and 1.6-1.8 pairs ha-1 of the macrophyte area) although fish density was very low. High water transparency probably compensated for low prey density, because potential prey could be readily detected. Most of the fish were small and occurred in the upper layers of the water column (they could not live below 10 m where the water was anoxic), so were readily available and easily caught by the grebes.