Degradation of CoastalDegradation of Coastal Ecosystems

NREM 612Dr. BrulandDr. Bruland

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Degradation of Coastal Ecosystems

I. Terminology

Coastal Zone (CZ): (many defs.) terrestrial area dominated by oceanicCoastal Zone (CZ): (many defs.) terrestrial area dominated by oceanic influences & marine aerosols, & marine area where light penetrates throughout (MEA 2005)

A. CZ boundaries (MEA 2005)

1. terrestrial/landward

a.

2 marine/sea ard2. marine/seaward

b.

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B. CZ Ecosystem Types

1. estuary: semi-enclosed areas (bay, lagoon) where seawater diluted w/ freshwater (Mann 2004)

2. beach: dissipative: larger waves, fine sand; reflective: smaller waves, coarse sedimentsediment

3. rocky shore: intertidal habitats with hard

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substrate, diverse topography & biota

4. mud flat: unvegetated intertidal zones w/ substrate ranging from sand-mud

5. tidal salt marsh (TSM): halophyticherbaceous veg (rushes sedgesherbaceous veg. (rushes, sedges, grasses) community occurring in temperate intertidal zones

6. mangroves (MG): halophytic shrub & tree community in sub/tropical intertidal zones

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7. sea grass bed (SGB): community of aquatic flowering plants fully-submerged in saline waters w/ sediment substrate (Mann 2004)

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a.

8. coral reef (CR): 3 main types, require clear, saline, tropical H2Os (Mann 2004)

a. fringing reef: found growing as fringe attached to land mass

b. barrier reef: occur @ some dist. out to sea creating a shallow lagoon bet reef & land

c. atoll: isolated structure surrounded by deep H2O that forms a ring of coral w/ central lagoon( Mann 2004)

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central lagoon( Mann 2004)

FILL IN THE FOLLOWING TABLE . . .

Coastal Ecosystem

Topography Energy Salinity Substrate

Sandy beachbeachRocky shore

Estuary

Mud flat

Salt marshSalt marsh

Mangrove

SSeagrass

Coral Reef

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II. Historical Background

A Humans often 1st inhabited sheltered areas near estuaries assoc wA. Humans often 1st inhabited sheltered areas near estuaries assoc. w. MGs, SGBs & reef-protected coasts

1. Later expanded to other coastal areas (MEA 2005)1. Later expanded to other coastal areas (MEA 2005)

2. Had pervasive influence on coasts & shifting baselines

B. Overfishing: 3 periods (Jackson et al. 2001):

1. aboriginal 10,000 ya: near shore, simple watercraft, localized

2. colonial 300 ya: exploitation by foreign mercantile powers, trade

3. global 50 ya: pervasive exploitation, human domination

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C. Historical sequence of human disturbances in coastal ecosystems

Climate change

Introductions

Human expansionMechanical habitat destruction

Pollution Altered ecosystems

Fishing

“Then” “Now”

(Jackson et al. 2001)10

1. Periods occur at diff times on diff continents

a. whales, manatees, dugongs, sea cows, monk seals, crocodiles, codfish, jewfish, swordfish, sharks, & rays now functionally or entirely extinct in most coastal ecosys.functionally or entirely extinct in most coastal ecosys. (Jackson et al. 2001)

i. lose Top Down control

b. adult populations of these spp. now number in 1000s rather than 10s of millions as they did a few centuries ago

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2. Natural vs human-modified CR food web

After FishingBefore Fishing

Bold font = abundantBold font = abundant

Normal font = rare

(Jackson et al. 2001)12

D. Species Introductions/Invasions

1. 1245 AD: Norse voyagers introduced soft-shelled clam (Myaarenaria) from North America to Baltic & North Seas (Lotze et al. 2006)

2. Many more intros follow

i. SF Bay & Pearl Harbor

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y

E. Coastal pop. explosion in last 100 yrs & urbanization

1. Ex.: in 1990, pop of Dade & Broward Cos., FL, was > pop of all 109 coastal counties from TX to VA in 1930 (Pielke 1995)

2 S C2. Similar story in many other CZs

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F. Alteration of river flows & sed loads

1. Globally, humans use > ½ FW runoff, 70% for ag (Vitousek et al. 1997)

S 2% fa. In US, only 2% of rivers unimpeded

b. Nile, Ganges, Colorado used so extensively, little H2O reaches sea (Vitousek et al 1997)reaches sea (Vitousek et al. 1997)

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G. Recent Legislation & Policy

1. 1972 CZM (Coastal Zone Management) Act

a. voluntary prog w/ fed assistance to states that dvp mgmt plans for CZs

i. unique fed-state collaboration

ii. amended, reauthorized from 1972-present

b. Many of 123 coastal countries now have CZM policies(Burke et al. 2001)

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2. 1972 MPRS (Marine Protection, Reserve, & Sanctuaries) Act

a. Designed to create & manage national marine sanctuaries in U.S.

b. Currently 16 Sanctuaries & 1 National Monument

i. Papahānaumokuākeaapa ā au o uā eaMarine National Monument Dedicated 5/2/2007

ii Mariana Trench MNM (nearii. Mariana Trench MNM (near Guam), Pacific Remote Islands MNM (S&W of Hawaii), Rose Atoll MNM )(East of Samoa) dedicated 1/6/2009

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3. 1975-Present: Various countries designate MPAs

a. 1975 GBR Marine Park MPA protects 10,000s km2 of SGBs & CRs

(Kaiser et al. 2008)

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b. 4,116 MPAs globally (Spalding et al. 2003)

4. 1973 ESA (End. Spp. Act)

a. Halophila johnsonii (Johnson's SG) listed as Threatened 9/14/98

5 1998 P Cli t E O d (EO) 130895. 1998 Pres. Clinton Exec. Order (EO) 13089

a. Est. US Coral Reef Task Force

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b. > $100 million to DOC & DOI for CR protection in U.S. &protectorates

III. Current Status & Future Trends

A 4 billi l i h bit l d /i 60 k f t (K i hA. ~4 billion people inhabit land areas w/i 60 km of coast (Kennish2002),

1 Nearly ½ of people living along coast have no access to1. Nearly ½ of people living along coast have no access to sanitation (MEA 2005)

B. MGs: 35% global loss rate (MEA 2005)B. MGs: 35% global loss rate (MEA 2005)

C. SGs: widespread decline (Botany Bay, Australia-2.4 fold , Tampa Bay, Florida, 3 fold , Fleets Bay, Virginia-17 fold )y y g )

D. CRs: 20% destr. globally in last few decades, >20% of remaining CRs degr (MEA 2005)

1.

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IV. Econ. Value of CZs

A CZ id $12 6 t illi US 1 $4 052 h 1 1 i iA. CZs provide $12.6 trillion US yr-1 or $4,052 ha-1 yr-1 in eco. services

Estuarine: $22,832 ha-1 yr-1 ($4.1 trillion yr-1)

SGB: $19,004 ha-1 yr-1 ($3.8 trillion yr-1)

CR: $6 075 ha-1 yr-1 ($0 38 trilion yr-1)CR: $6,075 ha yr ($0.38 trilion yr )

Shelf: $1,610 ha-1 yr-1 ($4.3 trillion yr-1) (Costanza et al. 1997)

B. Coastal fisheries estimated to be worth $34 bi yr-1 (MEA 2005)

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V. Causes of Coastal Degr.

A. Natural causes

1. Physical events:

hurricanes, tsunamis, storms

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B. Human-Induced Factors

1. Population

a. Coastal degr. blamed on pop growth

b. Coastal pop. pred. to approach 6 bi people by 2025 (Kennish 2002)

i. Coastal pop. density: 99.6 people km-2, inland pop. density: 37.9 km-2 (MEA 2005)

c. Dvping countries: vicious cycle of poverty, resource depletion, further impoverishment (Cesar et al. 2003)

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2. Economic

a Markets don’t value CZa. Markets don t value CZ services; encourage short-term exploitation

b. Uncontrolled dvpment & activity:

i. dvpment: shoreline structures, bldgs, marinas, harbors

ii. activity: dredging, shipping, recreation

c Jewelry & souvenir tradec. Jewelry & souvenir trade

i. pearls, abalone, coral in high demand

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demand

e. Marine aquarium market

i multi million $ industry trading live reef fish (Wabnitz eti. multi million $ industry trading live reef fish (Wabnitz et al. 2003)

f. Global growth of aquaculture (Golburg et al. 2001)

i. Ecuador: 50,000 ha of MG cleared for shrimp ponds since 1969 (MEA 2005)

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3. Political

a Failure to protect critical habitat breeding groundsa. Failure to protect critical habitat, breeding grounds

i. lack of enforcement of MPAs, other laws & legis, focus on single sppsingle spp

b. U.S. National Flood Insurance Program subsidizes coastal dvpt

i. starting in 1968, coverage for structure, contents (Beatleyet al. 1994)

c. Developers fund extensive lobbying

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4. Social

a Certain cultures object to no-take MPAs CZM policiesa. Certain cultures object to no-take MPAs, CZM policies

b. Many new inhabitants of CZs = retirees w/ unprecedented wealth & demands for local services, i.e. marinas, golf, fishingwealth & demands for local services, i.e. marinas, golf, fishing (Vernberg & Vernberg 2001)

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5. Land-based activities

a Veg removal from forestry ag RLs ↑ erosiona. Veg removal from forestry, ag, RLs ↑ erosion

b. NPS runoff of nutrients from ag & urban LUs, PS sewage & industial pollution from urban LUsindustial pollution from urban LUs

i. worst effects in dvping countries where treatment programs & gov’t controls deficient (Kennish 2002)

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6. Marine-based activities

a Tragedy of Commons: waste dumping marine debrisa. Tragedy of Commons: waste dumping, marine debris

b. Oil spills: effects on birds, fish, habitat, beaches, tidal zones

c. Ballast water discharge & invasive spp.

i. SF Bay~ 250 introduced plant & animal spp. (Cohen & Carlton 1995, 1998); 1 new spp intro every 14 wks bet 1961-1995

ii. Pearl Harbor: 48% of fish & benthic inverts sampled in 1997-1998 were introduced (Englund 2002)

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VI. Effects of CZ degr

A S di tA. Sediment

1. ↑ turbidity causes ↓ light penetration, ↓ PSN & ↓ coral growth (ISRS 2004)(ISRS 2004)

2. Smothers coral, requires ↑ energy for surface cleaning (ISRS 2004)2004)

3. Causes replacement of SGBs & CRs by MGFs

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B. Nutrients

1. Hypoxia linked to overstimulation of CZ by N & P

a. observed in Long Island Sound (NY), SF Bay, Gulf of Mexico, Baltic Sea, Black Sea, Coast of Queensland, Australia (Vitousek et al. 1997)

2 E i 1985 10 000 k 2 t h i2. Every summer since 1985 an area ~10,000 km2 turns hypoxic LA Gulf (Rabalais et al. 1999)

3 Replacement of coral by algae under high nutrient regimes3. Replacement of coral by algae under high nutrient regimes (ISRS 2004)

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C. Chemicals

1. Low conc. (even a few ppb) of herbicides & metals, ↓ PSN in corals (Harrison 1999, Jones et al. 2003)

D. Invasive Species

1. Cause habitat loss & alteration

2. Alter flow & availability of H2O

3 Cause excessive filtration of H O column disrupting estuarine3. Cause excessive filtration of H2O column, disrupting estuarine food web (MEA 2005)

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VI. Coastal BMPs, Solutions, Ways to Degr.

A Shift f i l t t b d t (EBM)A. Shift from single spp. to ecosystem based mgmt (EBM)

1. Include humans w/i broader context of environment, combine ecology & human dimensions into transdisciplinary EBM (Wilsonecology & human dimensions into transdisciplinary EBM (Wilson 1992, Naveh 2005, Weinstein et al. 2007)

2. Shift to mgmt. & policies that operate on ecological rather than2. Shift to mgmt. & policies that operate on ecological rather than

B. Meaningful engagement w/ stakeholders needed to create mgmt g g g ginitiatives that are credible, enforceable, & realistic

1.

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C. Conflict mitigation, consensus building, trade-offs, & compromise will become the norm for sustainable coastal mgmt.

D. Marine Protected Areas (MPAs), Env. Impact Assessment (EIA), Ecolabeling

34(Roberts 2007)