Geoscience Reference
In-Depth Information
2003a;.de.la.Huz.et.al..2005)..However,.this.may.be.a.declining.threat.with.the.immi-
nent.advent.of.peak.oil.
o
Ceanography
Climate. change. may. alter. both. horizontal. and. vertical. current. systems. via. raised.
water. temperatures. (Pearce. 2005).. If. so,. numerous. species. would. probably. be.
affected.because.many.migrate.either.as.larvae.(most.invertebrates).or.as.adults.(e.g.,.
turtles)..These.changes.may.arise.via.changes.at.large.scales.(e.g.,.changes.in.major.
current.systems).and.small.scales..The.latter.includes.possible.changes.in.near-shore.
currents.responsible.for.the.deposition.of.wrack.and.carrion.and.local.larval.trans-
port.and.retention..Furthermore,.more.energy.may.boost.coastal.upwelling.(IPCC.
2001)..This.would.transport.more.nutrients.to.the.photic.zone.and.enhance.photosyn-
thesis,.thus.increasing.the.food.supply.for.beach.ilter-feeders.
r
ainfall
Rainfall.is.likely.to.increase.in.some.regions.and.decrease.in.others.(CSIRO.2002)..
These.changes.may.affect.beaches.because.of.their.linkages.with.dunes.and.lagoons..
For.example,.rainfall.may.inluence.the.growth.of.dune.vegetation.with.consequences.
for.dune.stability.and.the.exchanges.of.sand.and.organic.matter.with.the.beach..In.
addition,.rainfall.changes.will.alter.the.discharges.from.estuaries.and.the.frequency.
of.natural.openings.of.coastal.lagoons..This.may.change.the.supply.of.sediment.and.
nutrients. from. terrestrial. catchments. to. the. sea. and. beach.. Also,. rainfall. changes.
would.alter.the.erodability.of.sand.and.the.level.of.the.water.table.of.beaches..In.turn,.
this.is.likely.to.affect.the.distribution.or.survival.of.burrowing.species.of.the.upper.
beach.via.desiccation.
a
CidifiCaTion
, C
alCifiCaTion
, a
Cidosis
While.CO
2
.in.the.atmosphere.is.relatively.inert,.it.becomes.highly.reactive.when.dis-
solved.in.seawater,.this.causing.the.pH.of.ocean.waters.to.fall.as.atmospheric.CO
2
.
levels.rise..In.fact,.the.pH.of.surface.waters.is.already.0.1.units.less.than.preindustrial.
levels.and.is.projected.to.decline.between.0.14.and.0.35.units.over.the.twenty-irst.
century. (IPCC. 2007)—changes. not. seen. for. about. 20. million. years. (Haugan. and.
Drange. 1996;. Brewer. 1997).. This. acidiication. can. potentially. affect. many. bio-
geochemical.conditions.and.processes.(Orr.et.al..2005;.Turley.et.al..2005),.and.its.
importance.has.prompted.a.theme.section.in.a.leading.marine.journal.(Vezina.and.
Hoegh-Guldberg.2008).
Because. lowered. pH. will. reduce. the. concentration. of. carbonate,. there. may. be.
both. physical. and. biological. consequences.. The. former. involves. the. reduction. of.
sediment.supply,.especially.on.carbonate.beaches..The.latter.involves.biological.cal-
ciication.rates,.which.will.decrease.in.oceanic.organisms.ranging.from.test-forming.
phytoplankton.to.scleractinian.corals.(Feely.et.al..2004)..Beach.taxa.such.as.mol-
lusks.and.crustaceans.are.also.dependent.on.calciication.because.they.have.robust.
protective. shells.. The. crustacean. exoskeleton. contains. chitin,. lipids,. and. proteins.
