Marine Flashcards
List the major physical featured of marine environments important in controlling the abundance and distribution of organisms:
Water salinity Temperature Light intensity Substrate Tides and wave velocity
What is primary production and what types of organism are,the primary producers in marine habitats?
Production of biomass (heat) through capture of solar energy
Phytoplankton and macroalgae, plants and cyanobacteria
What are the main physical and biotic features of seagrass habitats:
Physical: soft substrates, calm areas, depth dependant on water turbidity
Biotic: leaves are substrate for epiphytes and epizoa, swards form habitat, shelter and breeding ground for many fish and invertebrates
What are the main physical and biotic features of mangrove habitats:
Physical: soft marginal substrates that are sheltered and gently sloping and subjected to at least a 1m tidal range, generally restricted to above 24 deg isotherm.
Biotic: high primary production, nursery area for many fish, habitat for birds, bats and insects
What are the main physical and biotic features for salt marsh habitats:
Physical: under the 24deg isotherm, a tidal range of 0.5m or more, a soft substrate and protected shores.
Biotic: primary productivity, important to invertebrates and birds, detritus also important in food webs.
Compare and contrast the temperature regulation mechanisms of a poikilotherm such as marine jelly fish with those of a homeotherm such as a dolphin, a marine mammal. What are the advantages and disadvantages?
Poikilotherms cannot self regulate their body temperature so their internal temperature is the same as the external environment
Homeotherms regulate their body temperature through metabolic activity, muscular activity and or altered blood flow
Explain the principle of countercurrent exchange and give examples of its use in marine animals in temperature regulation and respiration:
Temperature regulation: counter currents are found in flippers and feet of endothermic animals in extremely cold environments. Arteries supplying these areas are deep inside the limb and give heat both to the tissues and the veins which surround them. Thus the blood returning to the body core is warmed.
Respiration: arrangement of blood vessels in gills allows counter currents to result in extra enrichment of blood with oxygen.
Explain the differences between osmoregulation and osmoconformers:
Osmoregulators maintaining concentration of dissolved substances inside their bodies different from those of the environment (marine birds, reptiles, mammals, fish)
An osmoconformer has cell contents at the same osmolality as the surroundings (most marine invertebrates, echinoderms, cephalopods, coelenterates, polychaetes and most marine molluscs and crustaeceans.)
What dispersal strategies are used by marine animals and how are these accommodated when designing marine reserves?
Dispersal strategies: mobile adults, crawl away larvae, planktonic larvae, dependent on ocean currents, or larvae that are strong swimmers.
Marine reserves should conserve the habitats of all stages of the life cycle of key organisms, should also be a source of propagules to populate adjacent areas.
