A Marine Environmental Recorder

An inexpensive Marine Environmental Recorder is described. The instrument system is small, lightweight and of low-power consumption. It is flexible, simple to operate and economical. It can be used remotely in a moored, buoyed or towed instrument system, recording measurements continuously for up to 24 h, or intermittently for 1 min every hour, for a period of up to 60 d. It has been used extensively in the Continuous Plankton Recorder and the Undulating Oceanographic Recorder to measure temperature, depth and occasionally chlorophyll and radiant energy; as a temperature recorder, it has a resolution of 0.1 Co, an uncertainty of measurement of ±0.1 Co and a stability of calibration within ±0.1 Co over a period of several months. With optional additional sensors for pitch, roll, vibration, acceleration and water-flow, the instrument system has been used to measure the performance of underwater towed vehicles and plankton samplers. The Marine Environmental Recorder is being incorporated into an instrument system in a data buoy, for automatically monitoring the marine environment in estuaries around the British Isles.

Measurement Of The Responses Of Individuals To Environmental-Stress And Pollution - Studies With Bivalve Mollusks

Certain physiological differences between individuals in different populations of the mussel, Mytilus edulis, are described. In particular, the scope for growth differs in space and time and may be used to assess the animals' physiological condition. When the required measurements are made in the field, the rates of growth predicted from the physiological data agree well with observed rates of growth. An alternative approach utilizes mussels transplanted to various waters, with indices of condition then measured in the laboratory under standard conditions; an example of this approach is illustrated. Laboratory experiments are used to equate various levels of physiological condition with fecundity, in an attempt to equate physiological effects on the individual with likely population damage. A cytochemical index of stress is described, based on the latency of lysosomal enzymes; spatial variability in this index, and its relation with the scope for growth, are discussed. Finally, the results of some experiments on the effects of petroleum hydrocarbons on mussels are described and the presence of inducible activity of NADPH-dependent tetrazolium reductase in the blood cells is demonstrated. Certain considerations that apply in adopting similar measurements of biological effects of pollution in environmental monitoring programmes are discussed.