Beach Biota
Rocky Intertidal
Salt Marsh
Tidal Flats
Plankton
Coastal Geomorphology
Ocean
Subtidal Ecology
100
What is the difference between epifauna and infauna?
Epifauna live attached to hard surfaces (like oysters, sponges, barnacles) or directly on top of the benthos (snails and starfish)
Infauna burrow in the sediments (like worms and clams)
100
What factors determine zonation patterns in the intertidal zones?
Tides, high temp, desiccation, predators, rugosity, competition, grazing
100
What can be done to conserve salt marshes?
Hydrological Restoration, Invasive Species Removal, Planting, Living Shorelines
100
Why might sediment smell bad and look black?
While the surface level is an oxic (dissolved oxygen present) environment, the deeper mud with its tightly packed fine silt is anoxic (little to no dissolved oxygen present). Redox zonation is the subdivision of natural environments based on the availability of oxygen.
100
What is the difference between holoplankton and meroplankton?
holoplankton - organisms that spend their entire life as plankton. Ex dinoflagellates, diatoms, krill, jellyfish, and copepods.
Meroplankton - organisms that take advantage of the water column during specific phases of their lifecycle. Examples include fish larvae, and the larval stages of many benthic invertebrates, such as lobsters, crabs, and snails. For some organisms this stage may only last for a few hours, whereas others may spend months or even years drifting in the currents.
100
Are Organisms and plants on the surface and bottom subjected to the same salinity range? What impact does that have?
Organisms and plants on the surface and bottom are not often subjected to the same salinity range. Stratification can occur when there is two water masses with different salinities. The surface water would be more fresh as it is less dense and the deeper water would have a higher salinity. Organisms have different tolerances for salinity, so these different ranges could cause there to be a different distribution of organisms that typically live in the surface waters versus deeper waters.
100
Describe the subtidal zone and its location.
The subtidal zone is commonly defined as the area below the lowest tide and often out as fas as the continental shelf. The subtidal zone remains submerged all of the time, with possible exceptions occurring during times of extremely low tides.
The subtidal zone extends to the continental shelf defined as the area of the seabed around a large landmass where the sea is relatively shallow compared with the open ocean.
The subtidal zone is a highly productive region because it is generally shallow, thus light penetrates the water, allowing photosynthetic organisms to thrive. There is also usually a great deal of input of organic matter from the shore and rivers, which means plenty of nutrients to fuel the food webs. This zone provides habitat to a large diversity of plants and animals
200
What is the difference between plankton and nekton?
Plankton - organisms carried by tides and currents as it is not strong enough to swim against them, often microscopic. (phytoplankton and zooplankton)
Nekton are organisms that are able to actively swim and are not at the mercy of the prevailing current.(fish, squid, marine mammals, turtles)
Many organisms start as plankton in their larval stages and grow to be nekton as they get older.
200
What are the roles of macroalgae in the intertidal?
Macroalgae play an important role as primary producers. Along with the production of food, macroalgae can also provide shelter and habitat for small fish and invertebrates and are important buffers against erosion as they help to stabilize sediments.
Rhodophyta or 'red algae,' Phaeophyta or 'brown algae,' and Chlorophyta or 'green algae:'
200
What threats do salt marshes face?
The restriction of tidal action bridges and culverts , Land Reclamation urbanization, Pollution, -All the major impacts mentioned above affect salt marshes not just by decreasing habitat area and destroying salt marsh species but also by changing the natural abundance and distribution of salt marsh plants and, thus, changing zonation patterns in these ecosystems.
200
What factors may determine the type, abundance, and distribution of plankton in the water column?
Light availability, nutrient concentration, salinity, tides, predation, and availability of carbon dioxide.
200
What are longshore currents and beach drift and why are they important concepts to study?
A longshore current is caused by waves approaching a beach at an angle and thus releasing energy for movement in a certain direction.
Beach drift is also caused by the waves breaking and swashing (back and forth) over a beach area at an angle.
Both these processes carry sediments that are suspended in the water or deposited on the shore. All these processes together are responsible for transforming and shaping the coastal areas and making them the naturally highly dynamic environment they are. They can be studied by looking at beach profiles.
200
Why may water quality parameters show heterogeneity throughout the harbor?
It is mostly due to freshwater input from the rivers (West River, Mill River, and Quinnipiac River) and seawater through Long Island Sound.
300
What is CPUE and how is it calculated?
" Catch Per Unit Effort " or CPUE. There are several ways to calculate CPUE, but the most simple and common method is to simply divide the total number of each species found by the total amount of time spent seining (in hours), which you can report in units of individuals/hour.
CPUE= # of organisms of species/ net time (hours)
300
What can observing rugosity tell you about an environment or the species you will find there?
This is a great way to quantify the complexity of the substrate. Ecologists use this measurement as an indicator of the available habitat (substrate) in a given area. In the rocky intertidal, one could predict that the higher the rugosity measurement, the more available space for benthic organisms such as macroalgae or invertebrates.
300
What factors determine zonation patterns in salt marshes?
Salt marsh plant species are land-based plants that have adaptations to deal with the daily influx of saltwater in the intertidal zone. Species found at the lower limits of the marsh, closer to the shoreline, are better at coping with this increase in salinity and flooding stress than those typically found farther from the water tides, salinity, nutrients,
300
What are harmful algal blooms? How can they impact the environment and humans?
There are some species of phytoplankton that produce powerful toxins, making them responsible for so-called "red" or "brown" tides or harmful algal blooms. These toxic blooms can kill marine life and people who eat contaminated seafood. Some people may experience respiratory symptoms (coughing, sneezing, tearing, and an itchy throat) when the organisms responsible for red tide are present in the water and the winds blow them onshore. Red tide can also irritate the skin. -dead phytoplankton sink to the ocean floor. The bacteria that decompose the phytoplankton deplete the oxygen in the water which can then suffocate animal life.
300
What can beach profiles tell us about a beach?
Beach profiles can inform us of seasonal changes:
Summer Beach (fair weather with low flat swell): You will see accumulation of sediment, beach growth, leading to a concave profile with broad berm and steep beach face. This is defined as a swell profile.
Winter Beach: High energy wave attack beach and transport sediment offshore, creating a shorter berm and flattened beach face and potentially a longshore bar. This is defined as a storm profile., can tell us about major storm events and Beach profiles can also help us keep track of man-made changes to the coast.
300
When sampling water on a boat the temperature of the surface sample is warmer than that taken at the deep samples. Your colleague thinks that the reading is wrong and you need to buy new equipment. Are they correct? Why or why not?
The surface water is typically warmer than the deeper water as the sun is heating the water on the surface layers. Also, cold water is more dense meaning it would sink.
300
What challenges do organisms in the subtidal world not have to worry about that intertidal organisms have to face?
Inhabitants do not need to deal with air exposure, large changes in temperature, salinity, or the like. Organisms in the subtidal zone can devote their energy to finding resources (food, mates, shelter, etc.) and avoiding predators. This is reflected in their morphology, physiology, and behavior.
400
How do you expect species A, B, and C to be distributed in the intertidal environment?
Species A is not very tolerant to desiccation and would therefore be better adapted to live in areas more exposed to submersion (high water exposure) and, since species A is also the better competitor of the three, it will dominate the zone near the waterline where it is well adapted to live. Species B cannot outcompete species A in areas of high water exposure but it can dominate areas that are more exposed to desiccation because species A is not as well adapted to dry conditions as species B. Although species C cannot outcompete A and B in areas of higher water exposure, it is well adapted to live in extreme dry conditions and it will, therefore, dominate the zone farther from the waterline.
400
Salt marsh plant species are land-based plants that have adaptations to deal with the harsh environment of the intertidal zone. What are some of the challenges associated with this environment?
They have adaptations to deal with the daily influx of saltwater in the intertidal zone. High concentrations of salt in the soil and water, as well as daily or occasional submersion depending on proximity to the shoreline. These plant species are well adapted to live in this environment and they benefit from changing tides that bring in the nutrients that help support their productivity.
400
Why might the composition/zonation of invertebrate organisms change as you go along a transect from high to low tide lines in a tidal flat?
The same spot may be scorching hot on a summer's day, well below freezing in the winter, and completely underwater for some part of the day. It can be fully saline while submerged at high tide, but flooded with fresh water if it is raining during low tide. Depending on the location, it may be routinely covered with fine silt or pounded by open ocean waves. Despite these challenges, intertidal habitats are diverse, productive, and important parts of the marine ecosystem. - Organisms that are better able to tolerate salt water, waves, and submersion are found low in the zone, while those that can tolerate heat, desiccation, or fresh water thrive higher in the intertidal. Biotic factors such as competition and predation are important too. Organisms that live lower in the intertidal are susceptible to marine predators that swim or crawl.-The upper intertidal is often exposed to terrestrial and airborne predators.
400
How can a secchi disk be useful when studying plankton?
A secchi disk can help us study the amount of plankton in the water since plankton can be a source of turbidity in the water column. Most water is turbid because of a mixture of mineral particles, organic matter, and plankton. If a small Secchi disk visibility reading is recorded, we may be able to correlate the high turbidity to the amount of plankton in the water column.
400
What are the parts of a wave?
Wave crest: Highest part of a wave.
Wave trough: Lowest part of a wave.
Wave height: Vertical distance separating the crest from the trough.
Wavelength: Horizontal distance between the crest of one wave and the adjacent wave.
Wave frequency: The number of wave crests passing a given point each second.
Wave period: The time required for wave crest to travel from one fixed point to another.
400
What are the 3 main habitats of the subtidal zone, how do they differ?
Sand habitats are the least complex of the range of habitats in Long Island Sound. Sand grains generally do not adhere to one another, preventing animals from constructing solid, walled burrows in the seafloor so many organisms bury themselves in the sand.
Boulder and gravel habitats are the most spatially complex habitats in the subtidal zone of Long Island Sound. These areas range in structure from large piles of boulders to flat pavements of small cobbles and pebbles. This provides a home for many encrusting and mobile organisms. Sessile invertebrates, crevices between and under boulders, as well as seaweeds and epifauna, provide cover from predators and refuge from swift currents.
Mud habitats are cohesive nature of fine silt and clay sediments of mud habitats as well as an abundance of nutrient-rich material provide an optimal habitat for many infaunal and epifaunal invertebrates.
500
What makes the rocky intertidal such a harsh environment? what adaptations might organisms have to deal with these challenges?
During low tide, organism risk desiccation and increased temperature due to the influence of sun and wind. Animals may be unable to feed or respire until the tide returns. They also must avoid predators from both landward and seaward. Salinity may fluctuate greatly due to variable runoff from the land. The intertidal is a highly stressful environment, competition! -strong attachment mechanisms to cling to rocks (like mussels gluing themselves on, or sea stars with tube feet), hard shells for protection from desiccation and wave impact, the ability to close up to retain moisture during low tide exposure, and the capacity to move quickly to find shelter in crevices when exposed to air, all to survive the fluctuating conditions of changing tides and wave action.
500
Why is it important to conserve salt marshes...what is their ecological value?
Salt marshes are nursery grounds; therefore, they directly or indirectly supports most of the commercial and recreational finfish and shellfish caught along our shores. They are also important components in water quality and coastal protection. Tidal marshes are among the most biologically rich and productive ecosystems in the world. Marsh plants are important primary producers, providing energy for higher trophic levels while their stems, roots, and rhizomes provide physical structure that makes these places vital "nursery habitat" for many different marine animals and both foraging and nesting habitat for a number of different birds.
500
Why are benthic organisms important? What might a typical food web/interaction system look like in a tidal flat?
Primary production by benthic algae and phytoplankton occurs at high rates on many tidal flats. Primary producers are then consumed by filter feeders such as clams and oysters. In turn, these species serve as food for larger, species such as blue crabs, striped bass, and a variety of coastal birds. As tides rise to cover the flats, juvenile fish often swim in from the nearby shallow subtidal zone to feed. High densities of crustaceans and shellfish thrive in sheltered tidal flats, making this habitat type an excellent foraging ground for migrating and wading shorebirds. Additionally, the bacteria, decomposers, and detritus-feeders living in the benthic environment break down waste products and dead plants and animals. This nutrient recycling through decomposition in the sediment occurs at a high rate. The presence of shellfish and bait worms for harvest and the important habitat services provided to finfish and horseshoe crabs make tidal flats an important part of the marine economy.
500
What is the importance of phytoplankton
Phytoplankton are responsible for creating the present atmosphere. It was cyanobacteria that produced enough oxygen to support aerobic respiration and diversification of early eukaryotes. Phytoplankton produce at least 80% of the oxygen that we breathe
Carbon dioxide is absorbed from the atmosphere by the ocean and used for photosynthesis. Some of this carbon is carried to the deep ocean when phytoplankton die, and some is transferred to different layers of the ocean as phytoplankton are eaten by other creatures, which themselves reproduce, generate waste, and die.
500
Why might wave lines change shape when interacting with the bottom, what is the result, and what is this called?
Wave lines (imaginary line connecting wave crests) change direction due to slowing down of the wave in shallower water (see figure below, left). When a part of the wave line reaches shallower depth first this causes that part of the wave line to slow down allowing the rest of the wave line to "catch up". The overall result could be that the wave lines mimic the coast line (see figure below, right). This phenomena is called wave refraction.
500
Why is it important to take dissolved oxygen and nutrient readings when testing water quality?
We can also have a heterogeneous distribution of parameters such as nutrients and dissolved oxygen. Nutrients, such as nitrate, are very important for growth of phytoplankton and are usually delivered to the system via freshwater sources. The growth of phytoplankton results in an increase in dissolved oxygen. Too low of a dissolved oxygen content will result in die-off of nekton and other species that rely on oxygen. Stratification of the water can lead to decreased levels of dissolved oxygen in deeper waters.