Academic literature on the topic 'Seashore biology'

This chapter discusses general patterns of brooding in decapod crustaceans from aquatic to terrestrial environments, addressing behavioral adaptations as well as costs and benefits. Brooding embryos is a common feature among decapods. However, brooding exhibits a wide range of modes that are highly dependent on the environment. Brooding is less common in marine systems, whereas there is a general pattern of extended brooding with terrestrialization. Exceptions are crabs that have invaded land directly via the seashore, i.e. land crabs that have indirect development like their marine ancestors. During terrestrialization, adaption to environmental stressors like desiccation, UV radiation, temperature variability, mechanical support, and osmolality seemed to generally favor decreasing larval development and increasing duration of brood care. Thus, crustaceans developed more complex brooding mechanisms as adaptive responses to the colonization of land (e.g., osmoregulation of the maternal fluids, marsupial fluid, sealed and specialized marsupium, provision of nutritious material, grooming and cleaning, ventilation of the embryo masses). However, clear brooding behaviors are also observed among several marine species (e.g. grooming and cleaning, oxygen provision). The major efforts to characterize general brooding patterns among decapod crustaceans and describe brooding behaviors were not accompanied by comprehensive studies to understand the costs and the benefits of brooding. Several studies have addressed the positive influence of the mother on embryo development, but the efforts to quantify the impact on embryo survival are still limited. This chapter identifies problems that need further consideration to reach a deeper understanding of the evolution of brooding in decapod crustaceans.

Population dynamics of plant species of coastal sand dunes is influenced directly, both above and below the soil surface, by a wide variety of organisms. Plants serve as sources of carbon and pathogens including viruses, insects, bacteria, fungi, birds, and mammals of various kinds. Some enhance plant performance while others have deleterious effects. Positive interactions include pollination of flowers by useful insects in return for nectar and pollen, nutrient acquisition from soil by mycorrhizal fungi in exchange for carbon and acquiring nitrogen (N) from N-fixing bacteria. In the history of co-evolution between plants and organisms over one hundred million years plants have developed many mechanisms to defend themselves from pathogens. Morphology may be altered by producing epicuticular waxes, developing trichomes over leaves, producing tough leaves with deposition of celluloses, lignin, suberin and callose, developing thorns on stems and branches or producing secondary plant metabolites that retard development, intoxicate or kill herbivorous insects. Herbivory may induce a plant to produce chemicals that signal to advertise the presence of insects feeding on them and attract parasites to reduce their numbers. Phenological escape is also employed, such as delay of leaf expansion during periods of insect abundance. Some indirect mechanisms of plant defence involve the use of insects such as ants for protection from other phytophagous insects. However, the predators have also evolved the ability to break down the defence mechanisms of the plant. For example, they may use phytochemicals for their own defence or as olfactory clues for feeding. In this chapter a brief account of organisms of the coastal dune communities, including species of the intertidal zone, scavengers of the sea coast, reptiles, birds, insects, mammals and their possible interactions with terrestrial vegetation is presented. For biological organisms of the seashore the intertidal zone is the most important for food and shelter. The sand-dwelling species of the seashore must be able to contend with four limiting factors: (i) rush of water from the approaching or receding high tide and pounding breakers, (ii) low salinity of the top surface of sand (iii) desiccation of surface by high winds and sunshine and (iv) extreme changes in temperature of topsoil.

Nereididae (littoral ones often referred to as ‘ragworms’) are probably the most familiar of annelids, both from textbooks in zoology and marine biology and from their occurrence on seashores around the world. They are widely employed in teaching, in laboratory experiments, and as bait for fishing.

Plant communities of the dune complex are a result of interaction between tolerance of plant species and sandy substrate, high wind velocities, salt spray, sand accretion and environmental heterogeneity. Propagules of many plant species are dispersed by water currents and deposited on the driftline. Most of these species find ideal conditions for germination but seedling establishment, growth and reproduction is denied to all but a few species with ecological amplitude sufficient to withstand the physical stresses associated with sand accretion, erosion and sandblasting in the highly disturbed environment. The distinct differences between habitats from the water´s edge to the inland grass-forest ecotone leads eventually to the establishment of ecologically distinct communities consisting of both plants and animals. The distinction is caused by sharp differences in the physical environment that may create sharp zones with abrupt or gradual blending of the two community types. In some locations these zones are relatively stable for long periods before any visible change occurs in the community depending on the recession of the shoreline, availability of new bare areas and the advance of communities towards the sea coast. The occurrence of plant communities in zones has been documented along sea coasts worldwide. This chapter examines the plant communities of the sand dune complex along seashores of the world. The following information has been assembled from Doing (1985), Dry coastal ecosystems Vol. 2 A, B, C, edited by Eddy van der Maarel (1993), Doody (1991) and Thannheiser (1984). It presents data on plant communities and ecology of each zone from various parts of the world. The species complement in the ´foredune complex´ in tropical, temperate and other regions around the world may be different, but their response to the prevailing environmental stresses of foredunes is convergent. In different world regions the boundaries between vegetation zones of the sand dune complex may not be defined sharply because of climatic variability, geographic location, physiography of the dune system and other factors peculiar to each location. Usually three to six different plant assemblages have been identified on the dune complex along sea coasts and lakeshores. A brief description of vegetation and ecological traits of species in each zone are presented below.