Marine Biology & Global Change Part Two

Exam 4

What are the additional consequences besides warmer temp?

- Ice Sheet Reduction

- Sea level rise
- Storm increase

Ice Update 2020

Ice Area New Low

High variability in the summer and lower variability in the winter

Lowest extent and area ever recorded was this March, 2025

sympagic species

Arctic ice sheet community

some are endemic - can not be found anywhere else

What does the antarctic community rely on

krill - pop size of krill is correlated with ice sheet area

Sea Level Rise globally

Rise in the next three decades (2050) is anticipated to be, on average: 10 - 14 inches (0.25 - 0.35 meters) for the East coast;
14 - 18 inches (0.35 - 0.45 meters) for the Gulf coast;
4 - 8 inches (0.1 - 0.2 meters) for the West coast;

8 - 10 inches (0.2 - 0.25 meters) for the Caribbean;
6 - 8 inches (0.15 - 0.2 meters) for the Hawaiian Islands; and 8 - 10 inches (0.2 - 0.25 meters) for northern Alaska.

What are the biological impacts of sea level rise

Depth increases Light decreases

Salinity increases in higher zones

Increase sediments in the water

Further decreases light

Storm and Precipitation

Hurricane form relatively over warm sea surfaces

likely that warming will cause hurricanes in the coming century to be more intense globally and have higher rainfall rates than present day hurricanes

Ocean Acidification

reduction in the pH of the ocean over time; due to uptake of carbon dioxide (CO2) by the ocean from the atmosphere

Reaction for Ocean Acidification

What was the latest CO2 reading

430.25ppm - has been increasing since 2015

What is pH and pCO2 trends linked with?

Dissolved inorganic carbon

pH will reduce by .3 unit to 7.8 in 2100

Biological Impacts

Calcifiers

• Reduced calcification

Fish

• Physiology • Life history

What is the impact on plankton?

Acidification will inhibit calcification by plankton

(pteropods, foraminifera, coccolithophores)

Impacts on corals

Acidification will inhibit coral ability to deposit

calcium carbonate and build reef structure

Impacts on calcareous, crustose coralline algae

Decrease in the taxonomic diversity of coralline algae with increasing acidification with more than half of the species lost in high pCO2 conditions.

And decrease in percent cover.

Impacts on fish life history

• Common prediction is that OA affects growth, especially during early life history

• Regulating acid-base balance of cells occurs via active ion transport, and requires energy

• Less energy therefore available for higher functions

Does acidification influence rates of mortality

Yes

• Effects on early life stages may continue after recruitment

• Juveniles reared in high CO2 treatments suffer higher predation mortality

Adaptation

change in behavior, physiology, structure, etc of an organism to be more suited to an environment

Hope for climate change besides adaptation

• Potential mechanism to counter rapid climate change

• Evolution can be rapid

Adaptation to ocean warming

• Symbiont generally viewed as ‘weaker link’

• Symbionts vary in their thermal resistance

• Some coral-symbiont combinations react better to thermal stress

• Variation on which natural selection can act

How did corals adapt

hosting thermally-resistant zooxanthellae

Acclimation

process or result of becoming accustomed to new environmental conditions

Involves physiological, anatomical and/or morphological adjustments within a single organism that improves performance in response to change

Transgenerational acclimation

occurs when the performance of offspring in a particular environment is improved when parents have experienced the same environment.