MB: Alien Species, Endangered Species

Accidental/incidental transport- aliens often arrive by accident through:

1. Ship Bottom: barnacles, algae, mussles (attach to the bottom of ships and get moved to new regions)

2. Ballast Water: Plankton, larvae, small crustaceans, pathogens (ships take in water in one port, release it in another ex: zebra mussels)

People transport species on purpose for what

• for food

• as pets

• to “solve” an ecological problem- misguided attempts to fix environmental problems

What are the characteristics of successful invading aliens?

• fast growth

• early reproduction

• lots of offspring

• tolarate many environmental conditions

• eat a variety of food

• few predators in new environment

• good dispersal (larvae), floating eggs, strong swimmers)

Examples of Invading aliens- Lionfish

Lionfish

• pacific organisms

• can vaccum up any little fish

• they are non-native and they are highly destructive

• rapid reproduction

• lack of predators

Examples of Invading aliens- Alien Algae

• brought to hawaii- affect Hawaiian coral reefs

• outcompete natives

• can form dense mats, smothering corals and changing structure of reefs and seabeds

Alien Alage: Caulerpa Taxifolia (killer algae)

• was in an aquarium in monocco, then it got out

• herbivores dont eat it

• causes a disaster in habitats, grow/spread very quickly

• form dense mats, releasing toxins that harm herbivores

• no predators

Unomia Stolonifera (invasive soft coral)

• since it is a soft coral, it doesn’t lay down a skeleton and it grows fast

• from south pacific

• grows as a mat that breaks into little pieces and are deadly to reefs and kills everything else

• suffocate native corals

Invasive Species: Mnenmiopsis

• seal walmnut/ comb

• spread rapidly causing ecosystem disruptions

• invades through ballast water and self feritlization

• vaoraciously eats zooplankton, reducing food for fish larvae

Invasive Species: European Green Crab

• one of the worst threatening native species

• agressive predators: eat native clams, oysters

• destroy nurseries and beds

• outcompete natives and rapid spread

Species become endagered for many reasons: Reason 1. Habitat destruction & pollution, warming surface water

threats include:

• Coastal development destroying wetlands, coral reefs

• Pollution (oil, plastics, toxic chemicals)

• Increased surface temperature → coral bleaching, shifting ranges

• Loss of sea ice (for seals, penguins)

• Sedimentation smothering seagrass/corals

2. Over Harvesting

Overfishing, hunting, poaching:

• Bluefin tuna

• Sea turtles (eggs, shells)

• Sharks (finning)

• Whales (historically)

When removal > reproduction → populations collapse.

3. Vulnerable Life Cycles

Vulnerable traits:

• slow growth

• mature late in life

• produce few offspring

• long migrations

ex:

• sea turtles (long juvinile stage, late maturity)

• sharks (few pups»long gestation): have very few babies, low reproduction, long pregnancies

• salmon (need specific river habitats)

Conservation: Use reproductive Value (Vx)

Reproductive value = how much an individual of age x contributes to future population growth.

• This helps determine which life stage to protect.

EX: Protecting:

• eggs: low reproductive value (most die anyway)

• juviniles: moderate

• Adults: high reproductive value

Alien species threat

• eat native species

• outcompeting them

• bringing diseases

• changing habitat structure (lionfish on reefs)

Depence on Other Species- Some endagered species rely on

1. Mutualisms

• corals need zooxanthellae

• clownfish need anemones

• clear fish need coral reef habitat

2. Structure

• kelp forests needed by certain fish

• mangroves needed by juvenile fish

• seagrass habitats needed by mantees/dugongs

3. Food Specializations

• blue whales» krill ONLY

• Hawksbill turles» sponges

0f these partner species or habitats are lost, the dependent species declines too

Traveling Species Examples- Fossil Reefs

• Fossil Reefers on carribean islands

• canal is narrow in panama

• water from this lake travels to boats, boats have to take up ballast water which is one way marine organisms can get through a fresh water canal)

Traveling Species Examples- Diadema Antillarum

• the caribbean long-spined black sea urchin

• gyres go over which way they run

Traveling Species Examples- Crown of Thorns Starfish ASK AB NOTES FOR THIS