MARINE POLLUTION AND HABITAT DEGRADATION

DEFINITION: Degradation of environment, caused by people; involves chemical/physical alteration (as opposed to resource harvest itself)

Degradation: Aspects include: aesthetic, threat to human health, threat to human resources (e.g., fish), threats to ecosystem that includes resource (e.g., old growth forest, including spotted owl)

TYPES OF POLLUTION

1. SEWAGE - NUTRIENT ENRICHMENT
-nutrient enrichment leading to algae blooms and hypoxia
-Sewage - solid waste, leading to BOD
-Nutrient enrichment leading to turbidity
-Disease-carrying bacteria, viruses


2. TOXIC SUBSTANCES
- organics
-metals

3. OIL POLLUTION

4. THERMAL POLLUTION - power plants

5. ACID RAIN (includes source of nitrogen, phorphorus)
IMPORTANT ISSUES:
1. Inputs -----> Responses
2. Monitoring

POINT SOURCES VS. NON-POINT SOURCES


MEASURES OF POLLUTION RESPONSE:

(1) Individual based - mortality (LC50 Concept),
(2) Community and ecosystem based: biodiversity, dissolved oxygen
(3) Pathway Approach - movement of a substance through individuals and ecosystems - body burden, trophic transfer


SEWAGE AND NUTRIENTS

SOURCES OF NUTRIENTS:
1. SEWAGE OUTFALL
2. STORM SEWERS (NYC -connected to sewers Combined Sewer Outfalls or CSOs)
3. COMMERCIAL FERTILIZER
4. ANIMAL WASTE

Primary Treatment: Turds and other solid material is intercepted, reduces deposition of solid material, deoxygenation of the water. Done for nearly all New York waters

Secondary Treatment: Solid material is stirred, allowing some decomposition. Releases nutrients such as ammonia, nitrate, phosphate into water. Solid material removed and disposed as sludge (oceanic disposal?)


Tertiary Treatment: Material is kept in tanks and treated in various expensive and sophisticated ways. Phosphate removed chemically, nitrates, nitrites, ammonia removed by encouraging denitrification (loss of N to atmosphere)

NEW YORK: SEWAGE IS 10% OF TOTAL FLUID DISCHARGE, TREATMENT: Primary for part of Manhattan, none for rest, secondary for rest of NYC


PROBLEMS:

1. BIOLOGICAL OXYGEN DEMAND - created by mainly solid material released into water - consumes oxygen, chemical and bacterial breakdown.

NYC philosophy - reduce BOD - has been successful over last 50 years. Even getting oxygenated water in summer in lower NY Harbor

2. NUTRIENT INPUT AND HYPOXIA - even with secondary treatment, nutrients enter estuary (also through runoff and ground water from nearby septic systems). Nutrients stimulate phytoplankton growth, phytoplankton sink and rest of thermocline - bacteria breaks them down ---> HYPOXIA. Also denitrification is usually rare so nitrogen stays in water --> ammonium for more bacteria. Must have water exchange to remove N.


Case of Hudson River
Upper harbor PP is 200 g C m-2 y-1
Lower NY Bay PP is 800 g C m-2 y-1
DOM input is 2 x that of Georgia estuaries
EXPORT of nutrients to NY Bight, LIS
(Barrage proposal)

3. PROBLEM OF TURBIDITY - nutrient release stimulates phytoplankton - creates turbid waters, kills sea grasses (eel grass Zostera marina) that are important for many fish and particularly scallops

4. PROBLEM OF NITROGEN REDUCTION AND MANAGEMENT - will reduction of nitrogen reduce phytoplankton?


TOXIC SUBSTANCES

Most problematic when (1) highly toxic (2) mobile in marine water and biological systems such as food webs (3) easily absorbed by marine animals or plants (4) easily passed on to humans (5) low rate of degradation in the environment

Organic toxics - includes variety of pesticides polyaromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), hydrocarbons derived from crude oil.

BAD combinations COMMONLY of toxic effects often at very low concentrations, low degradation rates, biological mobility (e.g., to fatty tissues in case of DDT)


PESTICIDES

Pesticides - used to kill insects that often carry disease or are simply annoying to people

e.g., kepone - insecticide that poisoned much of the James River Estuary(Chesapeake Bay) and killed Blue crabs, later dredging re-exposed buried kepone and fishery closed again.

DDT - first used to kill insects, principally to kill off malaria, carried by anopheles mosquito - spraying of crops, marshes and wetlands

Problems: very toxic, takes long time to break down, soluble in fatty tissues

Caused decline in raptorial birds, e.g., osprey, bald eagle, peregrine falcon, species at tops of food chains): effects on bird hormonal cycles, egg shell production (thinning)


DDT largely banned in NA and birds coming back (Peregrine falcon, osprey)

DDT higher in higher trophic levels of salt marshes of LI (Woodwell)

PCBs

PCBs- used for lubricants in heavy electrical equipment

Manufactured by Monsanto, used by G.E. on Hudson River Plant, material released in sediment. Dam opened in 1970s, material released over dam and spread throughout river.

Believed to be carcinogenic to people, is for mice - shut down striped bass fishery (they feed while in Hudson) but not shad, concentrations over 2 ppm considered dangerous, low rate of breakdown.

WHAT TO DO? DREDGE? WHERE TO PUT?


METALS, INCLUDING LEAD, MERCURY, CADMIUM

Chemical form of metal matters in toxicity and mobility

Mercury - toxic especially as methyl Hg, conversion mediated by bacteria (Hg -->CH4Hg)

from some pulp operations, various chemical plants

Minamata Japan: nervous disorders, 1950s-1970s - birth defects, Hg passes through placenta

Lead - from fuels, sewage, industrial applications - declining but still a cause of neurological damage, brain development.

Cadmium - sewage, batteries, electroplating - affects renal function, protein function


POLLUTION AND EVOLUTION

Foundry Cove NY - polluted by NiCd battery factory (1953-1970s) - exported Cd to Hudson River, also sediments were 10,000-250,000 PPM Cd - now cleaned up

local fauna - some evolved resistance to Cd, Blue crab has Cd, and there is a health advisory


OIL POLLUTION

- leaks from marine terminals
- leaks from offshore drilling
- tanker accidents
- washout of oil from settled areas

TANKERS
Torrey Canyon - 1967 - broke up on rockes, Intl waters off UK, 80 tons released, 40 tons burned on bombing, detergents very damaging, ship had complex multinational ownership

Exxon Valdez - 1989 - broke up on shoal in Prince William Sound, Alaska, 11 million gallons, no cleanup equipment there, subsequent hot washing of beaches and rocks


OIL TOXICITY

LEAST --> MOST TOXIC:
CRUDE --> REFINED

<5% -- 40-50% aromatics (cyclic unsaturated)

e.g., birds: direct toxicity from oil ingestion, oil collapses down feathers by also collapsing interlock of contour feathers.