Effect of galvanically induced surface potentials on marine fouling

This paper reports the effect of a galvanically produced negative surface potential on the accumulation of marine biofouling. The potential was created by connecting pieces of copper or stainless steel to a layer of Indium/Tin Oxide semiconductor deposited on glass. It was shown that the negative potential significantly reduced the accumulation of biofouling. As the conductive layer is transparent, the technique was used to protect the windows of commercial optical instruments. This technology could provide an inexpensive way of extending deployment times for marine instruments.     

Lottery coexistence models extended to plants with disjoint generations

Abstract. Neither conventional niche theory nor current lottery models offer a satisfactory theoretical scope for modelling coexistence of species with disjoint generations. South-African fynbos and Australian kwongan include many species which are killed by, and recruit only after, fire. We propose a density-dependent lottery model which accommodates the unusual demographics of these species. We show that coexistence requires density dependence in recruitment. The result applies to a wider class of populations than the one considered here. It is applied to non-resprouting species in fynbos and kwongan. We show that the lottery assumption of recruitment in proportion to propagules is often satisfied, while the production of such propagules is often density-dependent, and we discuss some evidence of mechanisms whereby this may occur.