Marine Ecology Review

Flashcards covering marine biology zones, ecological concepts like landscape and seascape ecology, nutrient cycles, and connectivity in marine environments.

Marine Biological Zones

• Categorized by their location relative to shorelines and the ocean bottom; influenced by temperature, light, water depth, bottom substrate, and interactions with other organisms.

• Pittman, 2018

Estuaries

• Where rivers flow into oceans,

• characterized by varying salinity, tides, and the influx of terrestrial sediments and nutrients

• highly productive

• Pittman, 2018

Salt Marshes

• Shallow coastal wetlands dominated by grasses and rushes,

• known for high productivity due to terrestrial nutrient input and the presence of salinity gradients that lead to zonation of plant species;

• provide food and protection for various animals.

• Pittman, 2018

Mangrove Forests

• Tropical coastal zones dominated by salt-tolerant, evergreen trees and shrubs whose roots trap sediments;

• provide nutrients to marine ecosystems and habitat to many animals but are threatened by human development.

• Pittman, 2018

Rocky Intertidal Zones

• Stable substrates for organisms that must cope with wet and dry conditions and changing salinity as tides rise and fall

• dynamic zones with dramatic conditions where organisms need to resist temperature and salinity changes.

• Pittman, 2018

Coral Reefs

• Restricted to warm, shallow water

• corals form large colonies with algal partners in symbiotic mutualism, extracting calcium carbonate to build skeleton-like structures that form large reefs providing structure for ecosystems.

• grow very slowly

• Pittman, 2018

Kelp Beds/Forests

• Found in temperate environments

• consist of large brown algae with leaf-like fronds, stems, and holdfasts, supporting a diverse marine community.

• Pittman, 2018

Pelagic Zone

• Open ocean beyond the continental shelves,

• divided into the photic zone (up to 200m, supports high densities of organisms) and deeper zones where energy is supplied by falling detritus;

• characterized by organisms adapted to avoid sinking.

• Pittman, 2018

Below photic zone

• temperature drops and pressure increases

• hard to live here

• no light here

• Pittman, 2018

Climate Regulation (Ocean) - benefits of healthy ocean

• Healthy oceans provide climate regulation by uptake of a quarter of CO2 emissions and through heat transport.

• Pittman, 2018

Blue Economy - benefits of healthy ocean

• Contribution of healthy global oceans to economy (such as EU approx. 5% GDP); including fisheries $240 billion p/a

• Pittman, 2018

Human impacts

• Pollutants and nutrients via rivers

• Commercial fishing— overharvesting of fish and whales

•  Increase in UV radiation due to stratospheric ozone loss

• Greenhouse gases—increasing water temperatures and ocean acidification.

• Not one place in the ocean that is untouched by human impacts

• Often places are touched by multiple human impacts + they interact with each other

• Pittman, 2018

Landscape Ecology

• Emphasizes the causes and consequences of spatial variation in surface features and biota across a range of scales.

• Pittman, 2018

Seascape Ecology

• An integrative, spatially explicit discipline emphasizing interactions between spatial patterns and ecological processes in marine environments.

• Pittman, 2018

Challenges in applying seascape ecology

• Marine realm is more heterogenous, fluid and interconnected that the terrestrial environment

• Pelagic ecosystems represent 3D continuum from the surface - changing all the time

•  SST, salinity, productivity gradients, currents

• Linnean and Wallacean shortfalls are even more pronounced in the sea than on land

• Most what is out there is unknown - Linnean shortfall

• Wallacean shortfall - incompleteness of our knowledge

• Pittman, 2018

Nutrients in Coastal Ecosystems

• In estuaries, mixing of salt and fresh water can impact nutrient chemistry;

• estuarine and salt marsh sediments often have low oxygen concentrations that limit decomposition.

• estuaries change in PH 0 can release nutrients bound to floor parties

• Pittman, 2018

Factors limiting Aquatic Primary production

• Interaction of nutrients and light structures aquatic biomes

•  the interaction of these two factors also regulates the rates of NPP(net primary productivity)

• Nutrient limitation is far more important than in terrestrial Ecosystems

• NPP in aquatic ecosystems is much more responsive to the limiting nutrient

• Pittman, 2018

 

Colimitation in Subtropical Ocean Gyres

• NPP in the subtropical gyres is very low and is co-limited by nitrogen and phosphorus

• Phytoplankton contain less phosphorus than nitrogen

• Relative proportions of dissolved nutrient concentrations in ocean virtually the same across the world’s oceans

• Pittman, 2018

Redfield Ratio

• Relative proportions of dissolved nutrient concentrations in ocean - nitrogen -phosphorus ratio.

• Pittman, 2018

Upwelling of nutrient rich waters

• Zones of upwelling are highly productive

• Important for fishing etc..

• Cold nutrient rich waters

• Conversion of nutrients coming up

• Net primary production as upward movement provides nutrients

• Pittman, 2018

Linking pattern and process

• Global positioning systems (GPS) allow ecologists in the field to document precise locations of species and other variables.

• Radiotelemetry allows tracking of animal movements and migration patterns.

• Data analysis and GIS continually improve with better computers and statistical methods.

• Pittman, 2018

Cultural Seascape Ecology

• Studies patterns of movement integrating the physical dimensions of ocean, coastal areas, and human interactions/relationships.

• Ban et al., 2018

4Cs of seascape ecology

Seascape Patterns through Indigenous Worldviews

• indigenous users of seascapes often create mental models of a seascape based on their observations

• Mapping local knowledges can reveal a complex understanding of seascapes within TEK frameworks and unique worldviews - Dr Noelani Puniwai

• Works with local communities to map their knowledge

• Ban et al., 2018