Tema 7 Flashcards
What factors influence the dynamics of the submareal environment?
Hydrodynamics (water column mixing), temperature (T), salinity (S), nutrient availability, substrate type, proximity to land, light, turbidity, and primary production.
How do temperature (T) and salinity (S) vary in the submareal environment?
Temperature and salinity tend to be similar at both the surface and bottom of the water column, though short-term or seasonal variations can occur.
How does primary productivity vary between neritic and oceanic waters?
Neritic waters (shallow coastal waters) tend to have higher primary productivity compared to oceanic waters (open ocean).
How do nutrient levels affect primary producers in the submareal environment?
Nutrient levels in coastal and nearshore areas directly support primary producers, influencing benthic food webs.
What is the effect of proximity to land on sedimentation rates in submareal environments?
Areas close to land tend to have higher sedimentation rates, influencing the types of substrates available for organisms.
What are lithogenic substrates in the submareal environment?
Lithogenic substrates come from rivers and often contain high amounts of sediment.
How do hydrodynamic forces influence sediment sorting in submareal environments?
Hydrodynamic forces cause sorting of particles, leading to more uniform sediment distribution or variability depending on water movement.
How do phytoplankton and suspended particles affect light availability in the water?
Phytoplankton and resuspended particles from rivers increase turbidity, which can reduce the depth of photosynthetic activity.
What are the types of soft substrates found in the submareal environment?
Soft substrates are dominated by sandy (superficial) and muddy (extensive) deposits.
How do submareal environments compare to intertidal environments?
The submareal environment shares many features with the intertidal zone, including similar substrates and hydrodynamic conditions.
What is the diversity like in submareal environments?
Submareal environments typically have greater diversity than other marine zones, hosting various organisms adapted to dynamic conditions.
How does substrate homogeneity vary in submareal zones?
The substrate in submareal zones is often flat, but the homogeneity can vary based on particle size, water movement, and sedimentation.
What factors affect population regulation in submareal environments?
Predators, species interactions, and competition regulate populations and community composition in submareal environments.
What is the role of predators in submareal environments?
Predators, including benthic carnivores and pelagic predators (e.g., squids), influence community dynamics.
What types of benthic fauna dominate soft-bottom submareal environments?
Infaunal deposit feeders, infaunal suspension feeders, and epifaunal deposit feeders dominate soft-bottom submareal environments.
What is trophic group amensalism in the context of submareal environments?
Deposit feeders dominate, excluding suspension feeders, leading to trophic group amensalism where deposit feeders facilitate suspension feeders by creating tubes and structures.
How do bottom currents influence sediment structures?
Bottom currents create sedimentary structures like ripple marks with unidirectional patterns.
What is the distribution of organic matter in submareal environments?
Organic matter is patchily distributed, including algae, kelp, seagrasses, and carcasses, which are redistributed by larval dispersal and recruitment.
What is the role of hard substrates in submareal environments?
Hard substrates provide three-dimensional habitats with higher diversity than intertidal zones, supporting rich, productive communities.
What challenges do algae face in submareal hard substrates?
Space availability is a limiting factor, and zonation of algae occurs based on competition and environmental factors.
What types of communities are found on hard substrates?
Rich epifaunal communities coexist with sparse infaunal communities, such as Pholas and Lithophaga.
How do herbivores adapt in hard substrate ecosystems?
Herbivores are dominated by slow-moving invertebrates with defense mechanisms like chemical defenses, regeneration, drilling-resistant shells, and erect structures.
What role do carnivores play in hard substrate ecosystems?
Carnivores regulate herbivore populations and influence community dynamics and energy flow in these ecosystems.
How do herbivore and carnivore interactions affect community dynamics?
Herbivore and carnivore interactions influence community structure, energy flow, and species populations in hard substrate ecosystems.
