Marine biology - Barrier Island Biology

Intertidal (littoral zone)

The area between high and low tide, characterized by fluctuating conditions that support a diverse range of marine life including algae, mollusks, and crustaceans.

Pelagic zone

the open ocean, encompassing the entire water column from the surface to the seafloor

Benthic Zone

The Benthic Zone is the ecological region at the bottom of a body of water, including the sediment. It's inhabited by diverse benthos and is crucial for nutrient cycling, influenced by factors like depth and substrate.

Subtitdal zone 

the area below the low tide line that is continuously submerged, except during rare, extreme low tides

Plankton

tiny aquatic organisms, both plant and animal, that drift in water bodies because they are unable to swim against currents

nekton

actively swimming aquatic organisms that can move independently of ocean currents, including most fish, marine mammals, squid, and some crustaceans

Phytoplankton

• microscopic, single-celled photosynthetic organisms that drift in the water column, forming the base of aquatic food webs by performing photosynthesis.

• Main producer of food for zooplankton

• Goldish, yellow or green in color (from algae)

Zooplankton 

microscopic or small animals that drift in water currents, making up a key part of the food supply in marine and freshwater ecosystems.

Meroplankton

organisms that spend only part of their life cycle drifting in the water as plankton before they mature and become free-swimming (nektonic) or bottom-dwelling (benthic) adults

holoplankton

organisms that spend their entire life cycle as free-drifting plankton.

autotroph

an organism that can produce its own food using light, water, carbon dioxide, or other chemicals

heterotroph

an organism that cannot produce its own food and must obtain energy and nutrients by consuming other organisms or organic matter

(coastal) Erosion

caused by both natural and human-induced factors

• Waves, tides, and currents are major drivers, constantly moving sediment on and off shore. Waves that are steeper and closer together, often associated with winter storms, tend to cause more erosion. 

• Rising sea levels and an increase in the frequency and intensity of storms lead to more severe erosion.

• The construction of shoreline structures like seawalls and groins can interfere with natural sediment movement

(Beach) Deposition 

when the sea drops or deposits material. This can include sand, sediment, and shingle, resulting in landforms of coastal deposition.

Jetty

a landing stage or small pier at which boats can dock or be moored. It’s to protect a coastline from erosion and maintain navigable channels for boats

Groin

a man-made structure, built perpendicular to the shore, to protect beaches from erosion by trapping sand carried by longshore currents.

Aerobic

relating to, involving, or requiring free oxygen.

Anaerobic

non oxygen needing

What is detritus? Why is it important? 

any loose, decaying organic and inorganic matter, such as dead plants, animal waste, rock fragments, and other debris. In a biological context, detritus is a crucial food source for decomposers and detritivores, supporting ecosystems by breaking down waste and recycling nutrients. 

What are the two primary causes for the migration of barrior islands?

1. Rising sea levels 

2. Weather and Storms 

What physical changes occur when you walk from the street at Avalon to the beach, passing through the maritime forrest?

Maritime forest - trees and pine trees to deflect wind to protect inland trees, waxy coating on plants to protect from salty, humid air. Salt-resistant plants

What special adaptations to plankton have to make them successful?

Plankton have developed features such as small size, buoyancy, and specialized structures (like flagella or spines) to help them remain suspended in the water column, aiding their survival and reproduction.

Why is the intertidal zone at a sandy beach a difficult place to inhabit for consumers?

The intertidal zone at a sandy beach is challenging for consumers due to constantly changing conditions like wave action, varying water levels, and exposure to air during low tide, which can lead to a lack of stable food sources and a harsh environment.

What common features do we find within the interstitial communities of the sandy beach and salt marshes? What are the differences? 

Common features include burrowing organisms, nutrient cycling, and interactions with water and sediment. Differences often lie in species composition, salinity levels, and the influence of tidal forces. There’s often greater biodiversity and organic matter in the salt marshes, while sandy beach interstitial communities may have a wider range of species adapted to dynamic coastal conditions.

How is a food chain represented on paper?

A food chain is typically represented as a linear diagram or flow chart that illustrates the transfer of energy through different trophic levels, starting from primary producers to various levels of consumers.

Problems associated with the intertidal zone 

Desiccation (Water loss)

Temp Changes

Salinity changes

Interrupted feeding

wave actions and tide

O2 availability and build-up of CO2

limited space

Suspention feeder

the capture and ingestion of food particles that are suspended in water

Deposit feeder

an animal that primarily obtains nutrition from organic matter in sediment or soil

5 factors that interact on a coastline

waves, tides, currents, sediment supply, and coastal geology

A coastline is a…

boundary 

what are the two greatest forces at work in the formation of barrier islands?

1. Rising Sea levels 

2. long shore currents

Where does sand come from?

eroding rock segments 

Why is it called a barrier island?

because it acts as a barrier between the open ocean and the mainland, protecting the coast from the energy of waves and storms

Why are barrier islands important?

they act as a natural buffer, protecting the mainland coast from storms and erosion, and also provide crucial habitats for a diverse range of wildlife

What is a berm?

a raised mound or shelf of earth, sand, or other material that serves as a barrier, divider, or decorative feature

Photic zone

the top layer of a body of water, like the ocean, that receives enough sunlight for photosynthesis to occur

Photic zone organisms

plankton, jellyfish and turtles

Benthic zone organisms

sea spiders, sea stars, sea cucumbers, gulper eels, rat-tail fish

Epifauna

animals that live on or are attached to the seafloor (barnacle and coral)

infauna

quatic invertebrates that live and burrow within the soft sediments of seabeds, lakes, and rivers (worms, crabs, crustaceans)

meiofauna 

minute animals living in soil and aquatic sediments.

interstital communities

the community of organisms living within the interstitial space, which refers to the pore spaces between sand or sediment grains.

Supraittoral

the area of a shoreline located above the high-tide line that is periodically dampened by sea spray and occasional storm waves.

midlittoral

the part of the shoreline between the high and low tide marks that is regularly exposed and submerged by the tides

subtidal

the area below the low tide line that is continuously submerged, except during rare, extreme low tides

Four Main Marine Ecosystems and one common trait  

Coral reefs, mangrove forests, kelp forests, salt marshes, open sea

All have high salinity levels

What is the greatest number for a food chain

4 to 5

Food chain example

phytoplankton -→ seaweed —> sea urchin —> helmet snail —> Fish —> Shark

Subrates on a beach

rocks, sand, mud, and dirt

What are longshore currents?

A flow of water that moves parallel to a shoreline created by a gravitational pull at an angle. 

Difference between horizontal and vertical zonation 

Horizontal = arrangement of organisms in distinct ecosystems parallel to the shore

Vertical = arrangement of organisms in layers from bottom to top in a specific location

examples of meiofauna in a sandy beach

copepods, nematodes, ostracods