\ International Council for C. H. 1982/L: l/Corr. the Exploration of the Sea Administrative Report Addendum 'BiologicalOceanography Committee

FINLAND 6/0 J. Lassig

Institute of Marine Research Phytoplankton, primary production, chlorophyll a and related parameters were studied every second week (twice during the ice period) at one station in the western part of the Gulf of Finland and at 15 stations in the entire Baltic Sea as stipula­ ted in theBaltic Monitoring Programme (Helsinki:Commission).

Zooplankton was sampled (Hensen net) three times a month (once during the ice period) at two coastal stations in the Gulf of Finland, one station in the Archipelago Sea and one in the Bothnian Bay. Zooplankton was sampled (WP-2 net) at 26 stations in the entire Baltic Sea according to the Baltic Monitoring Programme·, I Benthic macrofauna communities were studied in the deep areas of the Baltic Sea. The stations of the Baltic Monitoring Pr~gramme were included in the survey. The produciton and decomposition of organie matter in the pela­ gial were studied in the Gulf of Finland in eooperation with Tvärminne Zoologieal Station of the University of Helsinki.

Institute of Radiation Proteetion, Helsinki Benthos studies were carried out in the vieinity of two nuclear power plants, one in the Gulf of Finland and one in the Bothnian Bay. SampIes have been taken twiee at 9 stations at each plant. Phytoplankton, .ehlorophyll a and primary produetion studies were performed onee or twiee a month during the ice-free period around both plants. National Board of Waters, Water Research Office, Helsinki The influence of industrial pollution on the composition of th~ benthic macrofauna was studied in 4 areas in the Gulf of Finland, in 4 areas in~ the Bothnian Sea and in 3 areas in the Bothnian Bay. Phytoplanlcton primary production, chlorophyll a and phytoplank­ tcm;. .;,:·~~ were measured 6 times during the ice-free period at coastal stations in polluted areas and 4 times at about 80 stations in unpolluted areas of the Gulf of Finland and the Gulf of Bothnia. Special investigations were performed off several residential areas. Causes and effects of the decrease of Fucus vesiculosus were studied in the Archipelago Sea and the Gulf of Finland.

Water Conservation Laboratory of Helsinki City Macrobenthos studies were continued monthly during the ice­ free period at one-station off Helsinki, and 3 times at 14 stations off Helsinki and Espoo. Phytoplankton, primary production, chlorophyll a and bacteria were studied twice a month suring the ice-free period in eutrophied waters off Helsinki and Espoo at several stations, and zooplankton at 5 stations, from severely polluted bays to the unpolluted areas outside the archipelago. Bioassays for growth-limiting nutrients have been studied using Chlorella sp.

Tvärminne Zoological Station of the University of Helsinki The life cycle and general ecology of littoral and deep soft bottom macrofauna species were studied at several sites in the archipelago . The aquatic macrovegetation of the so called fladas in the inner • and outer archipelago were studied and studies on periphyton and Fucus vesiculosus were continued. Morphology and taxonomy of brackish water nanoplankton from the Tvärminne area and northern Baltic Sea were studied. In situ toxicity tests were preformed with planctonic autotrophs and heterotrophs. /

Abo Akademi, Turku Macrobenthos sampIes were taken at 19 fixed stations in the archipelago of Äland. Effects on phytobenthos of wave exposure caused by ferry traffic were studied. • -, 111 Phytoplankton and primary production were studied in semien­ closed meromictic bays in the Aland archipelago.

University of Turku

Dynamics of Mesidotean entomon (Isopoda) and production ecology of zooplankton were studied in the Archipelaqo Sea.

Effects of ferry trafficon fish and fishery were studied in the Archipelago Sea.

Monitoring of the Fucus vesiculosus?iocenose was continued. The utilization of the increased primary production in the water ecosystem was studied.

Macoma baltica was studied as an indicator of eutrophication. The effects of mineral oil residues on Mytilus edulis were ·investigated.

Fouling problems caused by organisms were. studied.

University of Oulu

Meiofauna as indicator.of eutrophication was studied 3 times during the year at 2 station and the macrofauna quality/and - - .... _. -_.. _. I composition at 5 stations 3 times during the ice-free period.

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