warming deep seas

8/14/2019 Warming Deep Seas

1/43

Warming Neptunes KingdomThe Impacts of Global Climate

Change on Marine EcosystemsBy

Edward L. MilesBloedel Professor of Marine Studies and Public Affairs

Senior Fellow and Co-Director

Center for Science in the Earth System, JISAO

University of Washington

Seattle, WA. 98195


2/43

The Keeling Curve


3/43

Peter Brewer. 2004 ICES LECTURE

My message is simple; there are massive, and until veryrecently unrecognized, changes of geologic scale takingplace in the ocean as we have entered the anthropocene

era, and these may very well have profound effects onocean ecosystems world wideocean chemistry is

being altered on a scale not seen for millions of years,and there are very basic questions on the impact on

ecosystems and biogeochemical cycles to which we donot yet have answers.


4/43

Framing the Problem: Climate in a Worldof Multiple Stresses

Increasing surface & sub-surface heat in theworld ocean.

Large scale changes in ocean chemistry (Feelyet al., 2004; Sabine et al. 2004).

Global overfishing--Fishing down the foodchain, (Pauly, 2003).

Land-based pollution of the coastal ocean(GESAMP, 2001). Proliferation of invasive species


5/43

Trends in Surface andSubsurface Heat in the World

Ocean


6/43

Major Sources of Dislocation for marineEcosystems: Changes in Surface and Sub-surface

Heat Levitus, Antonov, Boyer, and Stephens. 2000.

Warming of the World Ocean. SCIENCE. VOL. 287 (24 March).

Levitus, Antonov, and Boyer. 2005. Warming of the world ocean.GEOPHYSICAL RESEARCH LETTERS. VOL. 32,1029/2004GL021592.

Barnett, Tim P., David W. Pierce, Reinur Schnur. 2001. Detection ofAnthropogenic Climate Change in the Worlds Oceans. SCIENCE,

VOL. 292 (13 April).

[Barnett, Tim P. et al. 2005. Penetration of Human Induced Warminginto the Worlds Oceans. SCIENCE,VOL. 309 (8 July)].


7/43

Levitus et al.2000. Fig. 1.


8/43

Implications of Levitus et al. 2000 Results

On basis of limited data set for years 1948 1996 based on standard depthmeasurements from surface through 3000 m, composites of deep ocean T.data constructed for multiyear periods for each ocean basin and for worldocean as whole.

In each basin prior to mid-1970s, temperatures of all basins relatively cool;warming increasing from mid-1970s, particularly in N. Atlantic.

What looks like a significant PDO signal in both N & S Pacific in upperocean heat content. May be an NAO signal in significant increase in N.Atlantic and Indian Ocean increases in mid-1990s.

Global sea surface T. series from 1900 showing warming in 2 periods :1920 1940 & from 1970s. [This finding similar to changes in global meanT. for last century (IPCC, 2001)]. But increase in world ocean heat contentpreceding increase in SSTs.


9/43

The Implications of the Levitus et al 2005 Results

Between 1955 1998, world ocean heat contentbetween 0 3000 m increased 14.5 x 1022 J = mean T.increase of 0.037C at rate of 0.20 Wm- 2.

Large part of change occurring in upper 700 m of worldocean. Substantial regional variability observed.

Note that increase of 0.037C a very large increase,since a 0.1C increase roughly = mean T. change of

100C of global atmosphere if all heat instantaneouslytransferred.


10/43

Levitus et al. 2005.


11/43

Observed:matches modelhindcasts very well


12/43

Global Averaged Upper-Ocean Temperature

in Models

Pierce


13/43

in Models

in Models

Pierce



14/43


in Models

in Models

Pierce


15/43

Climate Impacts on Marine

Ecosystems


16/43

How Does Climate Affect Ocean Ecosystems?

Fish inhabit hydrographic structures consistingof temperature, salinity, and depth.

Ecosystems exist from the level of plankton onup the food chain.

Climate is a very large driver in the stability andproductivity of marine ecosystems by sustainingor changing habitat.

Multiple stresses now a significant threat;between sub-surface heat increases andincreasingly acidic ocean major changes instore. Prediction capability severely limited.


17/43

Climate impacts on ecosystems

DIRECT

Habitat suitabilitychanges thermal stress, or

thermal tolerances areexceeded, too littlesunlight, too much

current Timing shifts due to

temperature change

INDIRECT

Bottom-up Habitat change causes

changes in food-webproduction

Top-down changes in the

predator field

match-mismatch intiming


18/43

How Do We Know What We Know ConcerningClimate Impacts on Marine Ecosystems?

Via the fossil record over millennia--primarily through benthicinvertebrates ( Roy and Pandolphi, 2005).

Inferences re T. changes & shifts in ocean chemistry possible, aswell as fluctuations in sea level.

Focus on shifts in ocean circulation, surface & subsurface, andimplications for shifts in geographic ranges of spp., localizedextinction events, and changing phenology of plankton blooms withconsequent breaks in linkage between phytoplankton and thezooplankton that feed on them--changes which ricochet up the foodchain with community-scale effects.

But these effects do not occur equally across all spp.


19/43

Current Evidence from the North Pacific Ocean

In 20th century, shifts in PDO from cool to warm phaseresult in ~1C in SST major shifts in composition of

coastal ocean foodwebs.

Cold water forage fish & plankton in reduced abundance;warm water fish--mackerel, hake, sardines--significantlyincreased in abundance. Salmonid distribution in NCCSdeclining significantly (Field, 2004).


20/43

Bottom trawl surveys

in Pavlov Bay, Alaska

(source: Bottsford etal. 1997 Science)

19

60s

1970s

1980s

the North So th see sa in salmon prod ction has


21/43

the North-South see-saw in salmon production hasbroken down in the past few years -- and so has theregional coherence in coastal ocean temperatures

Warm PDO Cool PDO Warm PDO ???Cool PDO

spr

ingchinook

returnstoth

e

ColumbiaRivermouth

(100

0s)

Alaskapinkandsocke

ye

catch

(millions)

Pacific Decadal Oscillation (PDO)


22/43

upwelling food webs in our coastal ocean:

the California Current

Cool water, weak stratification

high nutrients, a productive

subarctic food-chain with

abundant forage fish and few

warm water predators

Warm stratified ocean, few

nutrients, low productivity

subtropical food web, a

lack of forage fish andabundant predators


23/43Field 2004


24/43

Source: NMFS acoustic surveys

And the top


25/43

PICES Conclusions re Effects of Regime Shifts inNorth Pacific Over 20th Century

Ecosystem responses to ocean climate most quickly detected inlower trophic levels, i.e., phytoplankton, zooplankton, andinvertebrates--rapid reproduction rates reveals fluctuations inabundance over short periods of time (PICES, 2004, Edwards and

Richardson, 2004). Now becoming clearer and clearer that climate variability and

change impact marine ecosystems most significantly via a bottom-up process (changes in primary productivity) and secondarily via atop-down process mediated through predator-prey interactions.

It is the bottom-up process that cascades all the way up the foodchain(Field, 2004; Ware and Thomson, 2005). Must think aboutplanktonic ecosystems and community structure and interactionsacross multiple trophic levels(Ruhl and Smith,Jr., 2004).


26/43

Findings re Planktonic Ecosystems and CodRecruitment in Northeast Atlantic

Very similar to N.E. Pacific. Same bottom-up/top-downpattern. Bottom-up process is primary driver (Richardsonand Schoeman, 2004; Beaugrand et al., 2003).


27/43

Recent Evidence of the Impacts ofClimate change on Marine

Ecosystems

A Focus on the Bering Sea and theNortheast Atlantic


28/43

The Northeast Atlantic

Study by Perry, Low, Ellis, and Reynolds(2005) with focus ondemersals,both exploited & unexploited spp.

North Sea warming by 0.6 C 1962-2001 and 1.05 C 1977-2001. 15of 36 spp. studied moving north--latitudinal changes combined withdepth.

Evidence of differential rates of shifts suggest possibility of alteringspatial overlap among spp. Disrupting interactions andcompounding phenological shifts.

Beaugrand et al (2003) with focus on cod in North Sea suggestingthat larval cod survival sensitive to variability in T. Rising T. sincemid-1980s modifying planktonic ecosystem in way that reducessurvival of young cod--the bottom-up process at work.


29/43

Concerning the Limits of What We Know and theSignificance of What We Dont Know

All the studies cited couple the physics to the biology; only 2consider explicitly the impacts of fishing effort as well as climatechange; none considers the increasing acidification of the worldocean; and none considers the increasing pollution of the coastal

ocean on a global basis.

In a word, we dont have reliable knowledge about the future ofmarine ecosystems in a world of multiple stresses where climatechange and the large anthropogenic footprint (overfishing andcoastal pollution) are the principal drivers.

Most urgent problem is almost total ignorance about the potentiallarge scale effects on marine ecosystems of an increasingly low pHocean.


30/43

So, What is To Be Done?

Constraints: tax cuts & deficits; 9/11 & homelandsecurity; Iraq; Mars; Katrina.

Unlikely that funds for large scale effort would come from

U.S. Govt. at present. So shift strategy to private sector in U.S. as catalyst--

NGOs, corporations, & foundations & try to getinternational participation beginning with UK RoyalSociety as lead into ICES community.

Agent is Heinz Center & four sector mode. Why Heinz?Miles on the Board. Feely & Langdon to participate inSteering Com.


31/43

What Strategy?

Four products: Seek funding for international meeting to define research agenda for

impacts of acidification on marine ecosystems. Use output to shoparound internationally and in U.S. for support. Choose large marine

regions and seek to begin with North Pacific & North Atlantic?? Connect levels of ocean acidification to thresholds and targets issue

as defined in FCCC. Seek separate foundation support for thatgroup in Heinz Center.

Create working group in HC for elaborating a methodology for a

bounded multiple stress analysis. Do the multiple stress analysis. Staggered products over 5-yearperiod initially.


32/43

References

Agostini, Vera. 2005.Climate, Ecology, and Productivity of Pacific Salmon and Hake.Unpublished Ph.D. Dissertation, School of Aquatic and Fishery Sciences, University ofWashington.

Barnett, Tim P., David W. Pierce, Reiner Schnur. 2001. Detection of Anthropogenic ClimateChange in the Worlds Oceans, SCIENCE, vol. 292(13 April), 270-274.

Barnett, Tim P. et al. 2005. Penetration of Human-Induced Warming into the WorldOceans, SCIENCE, vol. 309(8 July), 284-287.

Beaugrand, Gregory et al. 2003. Plankton effect on cod recruitment in the North Sea.NATURE, vol. 426(11 December), 661-664.

Botsford, Louis W., Juan Carlos Castilla, Charles H. Peterson. 1997. The Management ofFisheries and Marine Ecosystems. SCIENCE, vol 277(25 July), 509-515.

Brewer, Peter G. 2004. Beyond Climate: The Emerging Science of a Low pH-High CO2Ocean, ICES Annual Science Conference, Open Lecture, unpub. Doc.

Edwards, Martin and Anthony J. Richardson. 2004. Impact of climate change on marinepelagic phenology and trophic mismatch. NATURE, vol. 430(19 August), 881-884.


33/43

References, contd.

Feely, Richard A. et al. 2004. Impact of Anthropogenic CO2 on the CaCO3System in the Oceans. SCIENCE, vol. 305(16 July), 362-366.

Field, John C. 2004. Application of Ecosystem-Based Fishery ManagementApproaches in the Northern California Current. Unpub. Ph.D. dissertation,School of Aquatic and Fishery Sciences, University of Washington, 407pp.

Joint Group of Experts on the Scientific Aspects of Marine EnvironmentalProtection (GESAMP). 2001. A Sea of Troubles, (Geneva: UNEP), ReportNo. 70.

GESAMP. 2001. Protecting the Oceans from Land-based Activities,(Geneva: UNEP),Report No. 71.

Levitus, Sydney, John I. Antonov, Timothy Boyer, Cathy Stephens. 2000.Warming of the World Ocean. SCIENCE, vol. 287(24 March), 2225-2229. Levitus, S., J. Antonov, and T. Boyer. Warming of the World Ocean, 1955-

2005. GEOPHYSICAL RESEARCH LETTERS, vol. 32,1029/2004GLO21592, LO 2604.


34/43

References, contd.

Pauly, Daniel, et al. 2003. The Future for Fisheries. SCIENCE, vol. 302(21November), 1359-1361.

Perry, Allison L. et al. 2005. Climate Change and Distribution Shifts inMarine Fishes, SCIENCE, vol. 308(24 June), 1912-1915.

North Pacific Marine Science Organization (PICES). 2004. MarineEcosystems of the North Pacific Ocean. PICES Special Publication Number1.

PICES. 2005. PICES Advisory Report on Fisheries and EcosystemResponses to Recent Regime Shifts. North Pacific Marine ScienceOrganization, Sidney, Canada. 12p.

Richardson, Anthony J. and David S. Schoeman. 2004. Climate Impact onPlankton Ecosystems in the Northeast Atlantic. SCIENCE, vol. 305(10September), 1609-1612.


35/43

References, contd.

Roy, Kaustuv and John M. Pandolphi. 2005 Responses of Marine Speciesand Ecosystems to Past Climate Change in Thomas E. Lovejoy and LeeHannah (eds.), (New Haven and London: Yale University Press),160-175.

Ruhl, Henry A. and Kenneth L. Smith Jr. 2004. Shifts in Deep-Sea

Community Structure Linked to Climate and Food Supply. SCIENCE, vol.305(23 July), 513-515.

Sabine, Christopher L. et al. 2004. The Oceanic Sink for Anthropogenic CO2. SCIENCE, vol.305(16 July), 367-371.

Ware, Daniel M. and Richard E. Thomson. 2005. Bottom-Up EcosystemTrophic Dynamics Determine Fish Production in the Northeast Pacific.SCIENCE, vol. 308(27 May), 1280-1284.


36/43


37/43

IPCC C li t


38/43

IPCC Consensus on climatechange

Carbon dioxide and other greenhouse gases warm the planet (*****) Greenhouse gases have been increasing (CO2 up 32%) and will

increase for a long time, because of human activities (*****)

Pre-industrial ambient concentration of CO2 in atmos. = 282 ppmv;2005 = 380 ppmv. This higher than at any time in last 420k yrs. &maybe 20m.

The planet has warmed 0.4-0.8C (0.7-1.4F) since 1900 (****) Natural causes an unlikely explanation (***) Further warming of 1.4-5.8C (2.5-10.4F) by 2100, faster than any

time in at least 10,000 years (****)

[Most recent model inter-comparisons (Science,2004) provide est. ofclimate sensitivity of 3.0 -3.2 C.]

Revelle : Human beings are conducting an unplanned, uncontrolledexperiment on a planetary scale.


39/43

Spatial patterns ofclimate trends:Model versus Observed

Boreal Summer Mean:

Warming strongest over landin observations

Cooling in N. Hemisphereoceans in observations

Weaker land-seatemperature contrast in

models

Boreal Winter Mean:

Strongest warming in highlatitudes

Barnett et al., 1999


40/43

A 20th century climatology of North

Americas Pacific salmon

Warm periods favored increased salmon productionin Alaska but decreased salmon production in the

NW PDO variability caused coherence in warm and cool

periods in the NE Pacific for much of the century, but thePDO pattern was not prominent from the mid-1990s to

~2002 There are other factors influencing Pacific climate includingcentury-long warming trends


41/43

Stabeno & Overland. 2004. Fig. 1.


42/43

The Bering Sea/Shelf (Overland& Stabeno, 2004)

Depth-averaged Ts for 15 July-15 Sept. warmer by 2C,mean of 2001-2003 as compared to 1995-1997.

Primary pattern is transition from predominantly cold

anomalies (blue) to warm (yellow/red). 1976 marksbeginning of trend to warmer summers.

Decrease in sea ice delaying spring phytoplanktonbloom to later in season, out of synch. with max.zooplankton growth.

Consequence that spring phytoplankton bloom benefitsprimarily the benthic community; later zooplankton bloombenefits primarily the pelagic ecosystem.


43/43

Bering Sea/Shelf, contd.

Observed dislocations- large-scale biogeographic shiftsnorthwards in ecosystem of the Bering Sea involvingdemersals (very large & profitable fishery), walrus,

salmonids, etc. Other major shifts expected.

Demersals particularly sensitive to T changes in NCCS;pelagics markedly less so at surface(Agostini, 2005).

warming deep seas

Documents