Chapter 5 - Biology and ecology of Northwest Atlantic seaweeds

Abstract

Various types of seaweeds and their habitats are described for the Northwest Atlantic, including lithophytic, psamophytic, epiphytic, endophytic, and parasitic. Excessive epiphytic/epizoic growth may render host seaweeds vulnerable to drag and detachment, while parasitic taxa may cause stress and death of various hosts. Most red algal parasites are adelphoparasites that share a recent common ancestor with free-living host species. The complexity of algal habitats and increased space for associated organisms are due to small-scale variations in shape, size and texture. A description of diverse morphological and anatomical features that are useful for seaweed identifications is presented, as well as taxonomically important life history patterns. Local distributional and longevity patterns for open coastal and estuarine populations in southern Maine and New Hampshire are outlined, plus a strong estuarine reduction pattern. Seaweed community and zonation patterns for the Northwest Atlantic are described for rocky open coastal and estuarine/salt marsh habitats.