Marine Conservation Ecology

The Anthropocene

• Species extinctions increased with human population size

• From 1800 to 2014, human population rose with Baby Boomers and so did extinctions (6000)

• Extinctions by century

  • 1600s: 5 chordata

  • 1700s: 29 chordata

  • 1800s: 93 chordata and mollusca

  • 1900s: 438 chordata, mollusca, anthropoda, platyhelminthes, annelida

Human Footprint: Terrestrial

• 2009 graph

• Simulation to show what islands looked like prior to colonization

• Thought, what the earth was like before humans?

• Graph shows cumulative impact of direct pressures (light pollution, railways, roads, waterways

Human footprint: Marine

• Very high impacts all over the world

• Mostly medium to medium high impacts

• Most high in North Sea, along coastlines, etc

• Small human population and coastal watershed size predict light human impact, but do not ensure it, since shipping, fishing, climate change affect even remote locations

• Many anthropogenic drivers are not observable so they skew human impact to become higher without us realizing

Tragedy of the Commons

• When something belongs to no one, no one takes responsibility to take care of it. Such as fisheries.

• 1833; cattle dilemma, first coined

Population Growth and Carrying Capacity

• Carrying capacity: the max amount of individuals that a habitat can contain, max amount of resources to be used by population

Ecological Context

• When population overshoots carrying capacity, it goes down

  • ex: lack of food,competition, habitat loss, stochastic events

• MSY

• Stable equilibrium phase under MSY

• Density-dependent aspects

• Density independent (stochastic)

• Different extinctions

  • local extradition, extinct in the wild

The Population Dies Out

• Types of Extinction

  • local: a population or species is no longer found in the area it used to inhabit (mountain lions in NC)

  • ecological: too few members exist in area to continue to fill ecological niches

  • biological: no member of species are left on Earth

  • Background: low rates of species extinction (usually one at a time) taking place due to random processes over time

  • Mass extinction: whole groups of species becoming extinct (5 in Earth’s history, 50-95% of all species went extinct over time)

Evolutionary Context

• This cladogram demonstrates the phylogenetic relationships of species over time

• Speciation event → new species

• Species with similar attributes share a more recent ancestor

Marine vs Terrestrial

• the sea is much larger than land

• Seawater is much less transparent

• Sea is more 3-D

• The sea is geochemically downhill from land

• Nutrients can be unavailable for hundreds of years

• Humans eat much more terrestrial domesticated than marine wild spp.

• Technologies for killing wildlife are less selective and evolving faster

• Dispersal stages are usually smaller and dispersal much farther

• Pelagic ecosystems undergo rapid spatial shifts

• Primary producer and consumer biomass are much patchier in space and time

• Still waters run deep

At Risk: totoaba

• can get up to 300 pounds

• swim bladder can be medicine, black market harvests them

• takes 5 years to mature

• Exists in upper gulf of California

• Vaquita is very endangered, less than 100 left, tiniest cetacean, consumed as bycatch