Abstract: Triorganotin toxicants are disclosed that are made of mixed saturated and unsaturated four-carbon chains with double bonds at C-1 and C-3. Incorporation of these compounds into random 50:50 copolymers of methacrylic acid and methylmethacrylate produces copolymer compositions that may be used as antifouling coatings for ship hulls. Methods for manufacturing the triorganotin toxicants and the copolymer compositions are also disclosed.

Abstract: Stable isotope-labelled tetra-n-butyl(124)tin was synthesized by the reaction of n-butylmagnesium bromide with .sup.124 SnCl.sub.4 and tri-n-butyltin bromide was synthesized by bromine cleavage of the tetraalkyltin. The tri-n-butyl(124)tin compound labelled with the stable isotope .sup.124 Sn is useable in environmental, chemical and biological applications to determine the fate, uptake and metabolism of tributyltin compounds. This determination is made by tracing the chemical, biological and physical processes by using gas chromatography(GC) and electron impact low resolution mass spectrometry(MS). The simplified spectra of the isotopically enriched compounds leads to a twofold increase in detection sensitivity by the GC and MS techniques.

Abstract: Tributenyltin compounds containing double bonds at C-1 or C-3 or combinats thereof are synthesized from symmetrical tetrabutenyltins to offer a sufficient toxicity to function as a biocide or an antifoulant compound for ships' hulls and have an increased rate of degradation to be compatable with the environment.

Abstract: A device for monitoring low levels of light emission in a selected underwr environment is provided with a photodetector having a light sensitive surface oriented into the environment, the photodetector generating electrical signals which are representative of light impinging upon the light sensitive surface. A window is positioned between the light sensitive surface and the underwater environment to protect the photodetector from the underwater environment, and a first material is positioned between the window and the underwater environment to prevent biological growth upon the window. A second material is placed in cooperative relationship with the first material to shift the wavelengths of certain light photons occurring in the underwater environment from a first wavelength range to a second wavelength range, in order to increase the attenuation lengths of the photons before they pass through the window.