L15 Pollution and invasive species

Question 1

what are 4 pollution types?

Answer 1

noise, plastic, invasive species and oil

Question 2

what are 4 major oil spill events?

Answer 2

Torrey canyon 1967, 0.85 million barrels
Exxon valdez 1989, Alaska, 0.25-0.75 million barrels
Amoco Cadiz 1978, Brittany, 1.6 million barrels
Deepwater Horizon, 2010, mexico 4.9 million barrels

Question 3

What is the impact of oil spills?

Answer 3

variable due to volume, sea conditions, location, whether dispersant is used, type of oil.
However majority of oil pollution comes from sewage, maintanence and oil being poured away.

Question 4

How does oil pollution affect organisms

Answer 4

varied depending on the phenotypes and level of exposure.
Toxicity pathway - ingestion , accumulation of contaminants in tissue, DNA damage, loss of immune function, mass mortality of pelagic eggs/ larvae, loss of buoyancy and insulation.

Question 5

How long does it take to recover from oil spill pollution

Answer 5

Depends on species present and habitats. Initial recovery takes 2-5 years but oil has long lasting impacts, >20 years to overcome.
eg 5 years after exxon valdez spill, 2% oil remained on beaches and 13% in sediments.

Question 6

Effects on Gulf killifish after deepwater horizon spill, in marshes in gulf of mexico.

Answer 6

oil differentially affected populations og Gulf killifish
In location nearest spill, significant changes in expression of suites of genes in gill tissue. CYP1A1 gene - common marker of hydrocarbon bioexposure particlarly highly expressed close to oil spill. many genes up or down regulated.

Question 7

What are common plastic items that cause plastic pollution?

Answer 7

Nets, non durable goods inc packaging, bags and containers. Can find lots of these items along shoreline, or floating in the ocean, causes ghost fishing.
Microplastic much more abundant, and are distributed around the world. It is possible to track arrival through historic samples. From laundry and breakdown of large items.

Question 8

example of biological effects of microplastic pollution.

Answer 8

Lugworm, Arenicola marina - experimentally fed a partially microplastic diet. Decreased feeding activity, increased phagocytosis, less egestion and lower energy reserves. (Wright et al, 2013).
Plastics readily absorb pollutants. pollutant laden PVC fed to lugworm, pollutants concentrated within body wall and gut tissues.
Also causes changes to behaviour, reproductive biology and gene expression.

Question 9

How was it shown that plastic pollution effects breeding rate of pacific oysters?

Answer 9

Fed with polystyrene and had higher feeding rates. Decreased oocyte production and sperm velocity, lower larval production and growth.

Question 10

What sources of marine noise are there?

Answer 10

boat engines/propellers, seismic surveys, construction noise, military activity.

Question 11

evidence of noise pollution causing whale stress

Answer 11

Little evidence but seems likely due to knowledge.
Bay of Fundy, NYC, shipping lanes closed on 9/11/2001 due to terror attack. Right whale fecal samples during this closure time had lower concentrations of glucocorticoid hormones than when it was open.

Question 12

Experiment to show boat noise is harming damselfish

Answer 12

Simpson et al
Larval ambon damselfish are vulnerable when they settle on the reef to predation by the dusky dottyback.
Exp. 1 - larval damselfish placed on patch reefs, where predators were active. Patch reefs with boat noise more likely to have larval mortality.
Experiments in the lab found that in the presence of boat noise, they have a higher metabolic rate/use more O2 and are less able to detect predators. Fewer startle responses.
Shown in both lab and feild, they are more likely to be eaten in places where boat noise is preset.

Question 13

What are 5 globally important invasive species

Answer 13

lionfish
Caulerpa
european shore crabs
sea walnuts
zebra mussels

Question 14

How do species invade other areas

Answer 14

mainly through ballast water
aquaculture
pet trade

Question 15

example of invasion from aquaria

Answer 15

Pterois volitans, and Pterois miles (lionfish)
native to indopacific but spread rapidly across carribean.
extremely predatory, driven declines in native species. Concerns that these effects may amplify to other trophic levels.

Question 16

What species can be foundin ballast tanks?

Answer 16

Briski et al, 2012
screened 67 tanks and found macroinvert invaders in 7, including crabs, gastropods, anemones, bivalves and polychaetes. all would also contain non settled pelagic larvae too.

Question 17

how is the risk of invasions calculated?

Answer 17

using shipping routes
probability is greater at intermediate distances.
Close distance the species can already be native, or at least have native predators.
Far - travel may impair survival or environment is too different.
If a species has a high movement ability, it is more likely to establish or seek out the optimum habitat.
Time since invasion can be used to work out distributional range of invasive species.