Anticipated Effects of Climate Change on Coastal Upwelling Ecosystems

In the paper

“the Northern Hemisphere Hadley Cell is predicted to decrease in intensity while that of the Southern Hemisphere will increase in intensity [9].”

What the sources say

• Partly supported

  The AGCM sensitivity experiments section reports a weakening of the Northern Hemisphere Hadley circulation and slight strengthening of the Southern Hemisphere cell in the CMIP3 ensemble mean. But the Conclusions and discussion section says the change near and south of the equator is weak and subject to large intermodel variability, so an unqualified prediction that the Southern Hemisphere cell will intensify overstates the source. Page numbers are not available in the supplied passages. (LLM, conf=0.88)

  cites [9] Ma J, Xie S-P. Regional patterns of sea surface temperature change: a source of uncertainty in future projections of precipitation and atmospheric circulation. J Clim. 2013;26:2482–501. sourceExperimental — accuracy not yet measured

In the paper

“These small pelagic fish species often comprise a substantial portion of the total animal biomass in EBUS, and fluctuations in their abundance have both top-down and bottom-up effects [5], serving as a key trophic control for large populations of higher trophic-level seabirds, marine mammals, and a variety of commercially important fish.”

What the sources say

• Partly supported

  In “Consequences for Ecosystem Functioning,” the paper describes sardine and anchovy as a link between plankton and predators and says abundance shifts may affect both lower and higher trophic levels. “Impacts on seabirds” gives examples of effects on birds. The cited passages do not establish the claim’s more specific trophic-control role for marine mammals or commercially important predatory fish, and the paper frames the broader effects as expected rather than established in every case. (LLM, conf=0.84)

  cites [5] Schwartzlose RA, Alheit J, Bakun A, et al. Worldwide large-scale fluctuations of sardine and anchovy populations. S Afr J Mar Sci. 1999;21:289–347. sourceExperimental — accuracy not yet measured

In the paper

“This idea was originally supported by emerging interregional patterns of observed sea-surface wind stress, and has been periodically tested against time series of observed data in all four regional EBUS [12,13].”

What the sources say

• Partly supported

  Split into 2 atoms — 0 confirmed, 2 partially supported, 0 disputed, 0 misattributed, 0 unverifiable. Expand the claim to see per-atom verdicts.

  cites [12] Barton ED, Field DB, Roy C. Canary current upwelling: more or less? Prog Oceanogr. 2013;116:167–78. sourceExperimental — accuracy not yet measured
• Partly supported

  Split into 2 atoms — 1 confirmed, 1 partially supported, 0 disputed, 0 misattributed, 0 unverifiable. Expand the claim to see per-atom verdicts.

  cites [13] Cropper TE, Hanna E, Bigg GR. Spatial and temporal seasonal trends in coastal upwelling off Northwest Africa, 1981–2012. Deep-Sea Res Pt I. 2014;86:94–111. sourceExperimental — accuracy not yet measured

In the paper

“It is still unclear how these future shifts in the Hadley Cell might impact the ocean high-pressure systems [6], which are major drivers of upwelling winds and appear to be largely responsible for their variability [10].”

What the sources say

• ?Not checked — no full text of the sourcecites [6] Stocker TF, Qin D, Plattner G-K, et al. Technical summary. In: Stocker TF, Qin D, Plattner G-K, et al., editors. Climate change 2013: the physical science basis. Contribution of working group I to the fifth assessment report of the intergovernmental panel on climate change. Cambridge: Cambridge University Press; 2013.
• Supported

  The Abstract states that oceanic high-pressure systems dominate variability in upwelling-favorable winds, particularly in winter. It also notes an exception: oceanic highs and continental thermal lows have equal influence on Benguela summer winds. (LLM, conf=0.91)

  cites [10] García-Reyes M, Sydeman WJ, Black BA, et al. Relative influence of oceanic and terrestrial pressure systems in driving upwelling-favorable winds. Geophys Res Lett. 2013;40:5311–5. source

In the paper

“Some modeling studies [e.g., 44] also suggest that the increase in upwelling-favorable winds could effectively counteract enhanced thermal stratification.”

What the sources say

• Supported

  The Discussion and Conclusion (section 4, paragraph 25) says increased upwelling-favorable wind stress and wind stress curl overcome the unfavorable effect of increased stratification. The model also forecasts increased spring upwelling velocities despite a warmer, more stratified upper ocean, matching the citing sentence’s qualified claim. (LLM, conf=0.94)

  cites [44] Auad G, Miller A, Di Lorenzo E. Long term forecast of oceanic conditions off California and biological implications. J Geophys Res. 2006;111:C09008. source

In the paper

“Model experiments tracing the history of these waters in the North Pacific indicate that they are subducted from the surface layer at locations well offshore of the EBUS and may remain at depth for decades prior to being upwelled, in the meantime accumulating remineralized nutrients and carbon dioxide while oxygen is being consumed by respiration [51].”

What the sources say

• Partly supported

  Split into 2 atoms — 0 confirmed, 2 partially supported, 0 disputed, 0 misattributed, 0 unverifiable. Expand the claim to see per-atom verdicts.

  cites [51] Rykaczewski RR, Dunne JP. Enhanced nutrient supply to the California Current ecosystem with global warming and increased stratification in an earth system model. Geophys Res Lett. 2010;37. L21606. sourceExperimental — accuracy not yet measured

In the paper

“Upper ocean warming could increase water column stratification [37][38][39], potentially counteracting the effects of intensifying upwelling-favorable winds by reducing the efficacy of coastal upwelling to deliver nutrients to the euphotic zone.”

What the sources say

• ?Not checked — no full text of the sourcecites [37] Sarmiento JL, Hughes TMC, Stouffer RJ, Manabe S. Simulated response of the ocean carbon cycle to anthropogenic climate warming. Nature. 1998;393:245–9. source
• ?Not checked — no full text of the sourcecites [38] Roemmich D, McGowan J. Climatic warming and the decline of zooplankton in the California Current. Science. 1995;267:1324–6. source
• Supported

  The Summary and Conclusions (§5, ¶35) link long-term warming with enhanced stratification. The Biological Implications section (§4.3, ¶28) also describes near-surface warming leading to increased stratification and reduced input of nutrient-rich water. These passages support the warming–stratification point to which the citation is attached. (LLM, conf=0.92)

  cites [39] Palacios DM, Bograd SJ, Mendelssohn R, Schwing FB. Long-term and seasonal trends in stratification in the California Current, 1950–1993. J Geophys Res. 2004;109:C10016. source

In the paper

“A long-term trend toward declining oxygen content in the southern California Current has been observed, with the hypoxic boundary (defined as the depth at which dissolved oxygen is 60 uM/kg) shoaling by up to 80 m over the period 1984-2006 in the Southern California Bight [55,56].”

What the sources say

• Partly supported

  The Abstract reports declining dissolved oxygen in the southern California Current over 1984–2006. Section 3, paragraph 9, reports that the hypoxic boundary shoaled within the Southern California Bight, but gives a maximum of 90 m, not the claimed 80 m. (LLM, conf=0.90)

  cites [55] Bograd SJ, Castro CG, Di Lorenzo E, Palacios DM, Bailey H, Gilly W, et al. Oxygen declines and the shoaling of the hypoxic boundary in the California Current. Geophys Res Lett. 2008;35:L12607. sourceExperimental — accuracy not yet measured
• Partly supported

  Section 3.1, paragraphs [12–13], reports declining oxygen and a shoaling hypoxic zone in recent decades. It recounts Bograd et al.’s finding of up to 80 m of shoaling, but this paper’s own estimate is 65 m inshore. The paper defines hypoxia using 1.5 ml L−1, not the claimed 60 µM/kg boundary, and its time series ends in 2007 rather than 2006. (LLM, conf=0.88)

  cites [56] McClatchie S, Goericke R, Cosgrove R, Auad G, Vetter R. Oxygen in the Southern California bight: multidecadal trends and implications for demersal fisheries. Geophys Res Lett. 2010;37:L19602. sourceExperimental — accuracy not yet measured

In the paper

“although this decline has been attributed primarily to a change in the abundance of pelagic tunicates [42,43].”

What the sources say

• ?Not checked — no full text of the sourcecites [42] Lavaniegos BE, Ohman MD. Long-term changes in pelagic tunicates of the California Current. Deep-Sea Res Pt II. 2003;50:2473–98. source
• Supported

  The Discussion (§4.1) says the long-term decline in pelagic tunicates, particularly salps, accounted for the principal biomass variations measured by zooplankton displacement volume. The Conclusions (§5) likewise say this decline explains the previously documented decline in displacement volume. The paper distinguishes that measure from organic-carbon biomass, for which it found no long-term decline. (LLM, conf=0.92)

  cites [43] Lavaniegos BE, Ohman MD. Coherence of long-term variations of zooplankton in two sectors of the California Current system. Prog Oceanogr. 2007;75:42–69. source

In the paper

“Related to the concept of spring transition, upwelling winds in the California Current occur in distinct winter and summer seasonal Bmodes,^each with unique atmospheric drivers [10] and differential impacts on biological processes, as documented in rockfish (Sebastes spp.) growth and seabird reproductive success [85].”

What the sources say

• Partly supported

  Split into 2 atoms — 0 confirmed, 2 partially supported, 0 disputed, 0 misattributed, 0 unverifiable. Expand the claim to see per-atom verdicts.

  cites [10] García-Reyes M, Sydeman WJ, Black BA, et al. Relative influence of oceanic and terrestrial pressure systems in driving upwelling-favorable winds. Geophys Res Lett. 2013;40:5311–5. sourceExperimental — accuracy not yet measured
• ?Not checked — no full text of the sourcecites [85] Black BA, Schroeder ID, Sydeman WJ, Bograd SJ, Wells BK, Schwing FB. Winter and summer upwelling modes and their relevance to climate impacts and ecological response in the California Current ecosystem. Glob Chang Biol. 2011;17:2536–45. source

In the paper

“and has been applied to cod stocks in the North Sea [90] as well as salmon and seabirds in California [82,91].”

What the sources say

• ?Not checked — no full text of the sourcecites [90] Beaugrand G, Brander KM, Lindley JA, Souissi S, Reid PC. Plankton effect on cod recruitment in the North Sea. Nature. 2003;426:661–4. source
• ?Not checked — no full text of the sourcecites [82] Sydeman WJ, Bradley RW, Warzybok P, et al. Planktivorous auklet Ptychoramphus aleuticus responses to ocean climate, 2005: unusual atmospheric blocking? Geophys Res Lett. 2006;33:L22S09. source
• Supported

  The Introduction (§1, paragraph 3; page not provided) describes hypothesized mismatches between krill availability and both coastal seabirds and juvenile salmon in California. The North Sea cod portion has a separate citation and is not attributed to this source. (LLM, conf=0.92)

  cites [91] Dorman JG, Powell TM, Sydeman WJ, Bograd SJ. Advection and starvation cause krill (Euphausia pacifica) decreases in 2005 Northern California coastal populations: implications from a model study. Geophys Res Lett. 2011;38:L04605. source

In the paper

“In another example, delayed transition to upwelling is hypothesized to have resulted in a temporal mismatch between arrival of coho salmon smolts at sea and food production from upwelling [92].”

What the sources say

• Supported

  The Conceptual model proposes that a mismatch between the onset of upwelling and smolt migration could leave smolts without favourable habitat on arrival at sea. The Discussion states more specifically that a later spring transition may contribute to poor coho survival through a temporal mismatch between smolt arrival and seasonal increases in food production in nearshore upwelling habitat. This matches the citing sentence’s description of a hypothesis, not an established causal finding. (LLM, conf=0.94)

  cites [92] Logerwell EA, Mantua N, Lawson PW, Francis RC, Agostini VN. Tracking environmental processes in the coastal zone for understanding and predicting Oregon coho (Oncorhynchus kisutch) marine survival. Fish Oceanogr. 2003;12:554–68. source

In the paper

“Increases in spring and summer upwelling intensity, and associated increases in the rate of offshore advection, are expected.”

In the paper

“The BH suggests that under global warming, continental temperatures will rise faster during the local heating seasons than will temperatures in the nearby ocean, thereby steepening the cross-shore pressure gradients that drive upwelling-favorable winds (Fig. 1b, c).”

What the sources say

• ?Not checked — no full text of the sourcecites [11] Bakun A. Global climate change and intensification of coastal ocean upwelling. Science. 1990;247:198–201. source

In the paper

“Marine mammals and seabirds that are tied to sparsely distributed nesting or resting grounds could experience difficulties in obtaining prey resources, or adaptively respond by moving to more favorable biogeographic provinces.”

In the paper

“but warming may also have direct negative impacts on the production of phytoplankton and zooplankton.”

In the paper

“These eastern boundary upwelling systems (EBUS) are among the most productive of the world's marine ecosystems [1,2].”

What the sources say

• ?Not checked — no full text of the sourcecites [1] Ryther JH. Photosynthesis and fish production in the sea. Science. 1969;166:72–6. source
• ?Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  cites [2] Cushing DH. Upwelling and fish production. FAO Fish Tech Pap. 1969;84:40.

In the paper

“With upwelling intensification, ocean acidity will rise, affecting organisms with carbonate structures.”

In the paper

“If changes to physiological functions are substantial, variation in species' abundances can translate into changes in productivity, phenology, and community composition, hence interspecific relationships and ecosystem functions [28].”

What the sources say

• ?Not checked — no full text of the sourcecites [28] Parmesan C. Ecological and evolutionary responses to recent climate change. Annu Rev Ecol Evol Syst. 2006;37:637–69. source

In the paper

“This pattern of increased upwelling-favorable wind intensity could be due to other climate-related mechanisms, such as natural multi-decadal climate variability, but the likelihood of significant greenhouse gas-related interactions cannot be dismissed.”

In the paper

“Changes in the water column include greater stratification, greater rates of upwelling, and greater offshore transport as well as the offshore migration of the upwelling front”

In the paper

“In EBUS, alongshore winds interact with the earth's rotation to force surface waters offshore, thereby pumping (i.e., Bupwelling^) nutrient-rich deeper waters into the illuminated surface layers in the coastal zone [3,4] where they are available for photosynthesis.”

What the sources say

• ?Not checked — no full text of the sourcecites [3] Sverdrup HU. On the process of upwelling. J Mar Res. 1938;1:155–64. source
• ?Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  cites [4] Wooster WS, Reid JL. Eastern boundary currents. In: Hill MN, editor. The sea, vol. 2. New York: Interscience Pub; 1963. p. 253–80.

In the paper

“Intensified upwelling-favorable winds [11] would lead to an increased upwelling rate, greater turbulence in the upper ocean, and swifter offshore transport of surface waters.”

What the sources say

• ?Not checked — no full text of the sourcecites [11] Bakun A. Global climate change and intensification of coastal ocean upwelling. Science. 1990;247:198–201. source

In the paper

“While enhanced upwelling may lead to enhanced nutrient enrichment”

In the paper

“In addition, changes in species composition of phytoplankton and zooplankton communities are a likely result that in turn may impact successively higher levels of the trophic web.”

In the paper

“may be able to take advantage of low-oxygen environments.”

In the paper

“Such events, some extending over more than 20, 000 km 2 of ocean surface [64][65][66][67][68], have been repeatedly observed near the coast of Namibia, resulting in widespread mortality of marine life and corrosive, foul-smelling emissions over land.”

What the sources say

• ?Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  cites [64][65][66][67][68]

In the paper

“Over interannual to decadal time scales, increased zooplankton biomass [45][46][47] and variability in the productivity and abundance of zooplankton, fishes, and higher predators of the California Current have been attributed to the meridional position of the North Pacific Current [48][49][50].”

What the sources say

• ?Not checked — no full text of the sourcecites [45] Wickett WP. Ekman transport and zooplankton concentration in the North Pacific Ocean. J Fish Res Board Can. 1967;24:581–94. source
• ?Not checked — no full text of the sourcecites [46] Chelton DB, Davis RE. Monthly mean sea-level variability along the west coast of North America. J Phys Oceanogr. 1982;12:757–84. source
• ?Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  cites [47] Chelton DB, Bernal PA, McGowan JA. Large-scale physical and biological interaction in the California Current. J Mar Res. 1982;40:1095–125.

In the paper

“Consequently, the total amount and offshore extent of new primary production might increase.”

In the paper

“The biological impacts of these events can be catastrophic, with widespread mortality of macroscopic benthic organisms, resulting in periodic dead zones such as those observed on the Oregon continental shelf [61].”

What the sources say

• ?Not checked — no full text of the sourcecites [61] Grantham BA, Chan F, Nielsen KJ, Fox DS, Barth JA, Huyer A, et al. Upwelling-driven nearshore hypoxia signals ecosystem and oceanographic changes in the northeast Pacific. Nature. 2004;429:749–54. source

In the paper

“Phytoplankton and zooplankton would be transported more rapidly toward convergent offshore frontal systems, which themselves may be forced further offshore (Figs.1b, c and 2) [3,34,35].”

What the sources say

• ?Not checked — no full text of the sourcecites [3] Sverdrup HU. On the process of upwelling. J Mar Res. 1938;1:155–64. source
• ?Not checked — no full text of the sourcecites [34] Barth JA. Stability of a coastal upwelling front. 2. Model results and comparison with observations. J Geophys Res. 1989;94:10857–83. source
• ?Not checked — no full text of the sourcecites [35] Marañón E, Fernández E. Changes in phytoplankton ecophysiology across a coastal upwelling front. J Plankton Res. 1995;17:1999–2008. source

In the paper

“With strongly enhanced upwelling, the rate of offshore transport of surface waters would increase, potentially leading to problematic consequences.”

In the paper

“Furthermore, the marked difference in ontogeny, generation times, and swimming capabilities between phytoplankton and zooplankton may result in a spatial mismatch between herbivorous zooplankton and their phytoplankton forage, and/or flushing of any weakly mobile organisms from favorable habitats associated with the near-coastal upwelling zone [36].”

What the sources say

• ?Not checked — no full text of the sourcecites [36] Bakun A, Weeks SJ. Greenhouse gas buildup, sardines, submarine eruptions, and the possibility of abrupt degradation of intense marine upwelling ecosystems. Ecol Lett. 2004;7:1015–23. source

In the paper

“With low to moderately strong upwelling, upwelled nutrients would support a robust phytoplankton community (Fig. 2), which would in turn sustain flourishing zooplankton and upper trophic level communities.”

In the paper

“As a result, deep waters supplied in the future by upwelling may be characterized by increased macronutrient concentrations, reduced pH, and decreased oxygen concentrations.”

In the paper

“Based on a regional climate model, upwellingfavorable wind stress curl off northern California is hypothesized to shift to later in the year in response to an increase in CO 2 concentrations [19].”

What the sources say

• ?Not checked — no full text of the sourcecites [19] Snyder MA, Sloan LC, Diffenbaugh NS, Bell JL. Future climate change and upwelling in the California Current. Geophys Res Lett. 2003;30:1823–6. source

In the paper

“If the timing of upwelling changes, a temporal mismatch between fish larvae and their food may reduce survival.”

In the paper

“This process will lead to more acidic waters which will make it increasingly difficult for important lower trophic level marine organisms, such as oysters and pteropods, to precipitate calcium carbonate (CaCO 3 ) to form shells and exoskeletons [72][73][74].”

What the sources say

• ?Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  cites [72][73][74]

In the paper

“Despite high levels of conservation concern, the impacts of climate change on seabirds and mammals remain relatively under-studied.”

In the paper

“Finally, another hypothetical response may be that climate change and overfishing might jointly promote explosive population growth of less mobile and anoxia-tolerant planktivorous jellyfish [93][94][95][96].”

What the sources say

• ?Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  cites [93][94][95][96]

In the paper

“Changes to the timing of these modes and transitions may be biologically relevant”

In the paper

“Yet when upwelling is too strong, turbulence and offshore advection could decrease fish production due to disruption of feeding strata [87,88] and/or excessive offshore transport of planktonic larvae and prey away from favorable coastal habitats [86,89].”

What the sources say

• ?Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  cites [87] Lasker R. Field criteria for survival of anchovy larvae: the relation between inshore chlorophyll maximum layers and successful first feeding. Fish Bull. 1975;73:453–62.
• ?Not checked — no full text of the sourcecites [88] Peterman RM, Bradford MJ. Wind speed and mortality rate of a marine fish, the northern anchovy (Engraulis mordax). Science. 1987;235:354–6. source
• ?Not checked — no full text of the sourcecites [86] Cury P, Roy C. Optimal environmental window and pelagic fish recruitment success in upwelling areas. Can J Fish Aquat Sci. 1989;46:670–80. source
• ?Not checked — no full text of the sourcecites [89] Ainley DG, Sydeman WJ, Parrish RH, Lenarz WH. Oceanic factors influencing distribution of young rockfish (Sebastes) in Central California: a predator’s perspective. Cal Coop Ocean Fish Invest Rep. 1993;34:133–9.

In the paper

“Similarly, the best fish production may occur when the timing or spatial distribution of prey is well-matched to the ecological needs of the (fish) predators; this is known as the match-mismatch hypothesis [23]”

What the sources say

• ?Not checked — no full text of the sourcecites [23] Cushing DH. Plankton production and year-class strength in fish populations—an update of the match-mismatch hypothesis. Adv Mar Biol. 1990;26:249–93. source

In the paper

“EBUS can therefore be characterized as both resilient (quick recovery from disturbances) and robust (maintenance of ecosystem function and relatively high productivity) to natural climate variability, maintaining an abundance of species of high commercial and conservation value.”

In the paper

“Changes in the water column include greater stratification, greater rates of upwelling, and greater offshore transport as well as the offshore migration of the upwelling front”

In the paper

“Anticipated changes include the poleward migration of the Oceanic High and source waters.”

In the paper

“yet the impacts of climate change could be profound and difficult to forecast as they begin to exceed recent millennial ranges of precedent variability.”

In the paper

“An increasing incidence of hypoxia or anoxic events is likely to lead to the increased occurrence of dead zones, noxious gas emissions, and vertical compression of suitable habitats.”

In the paper

“Spatial or temporal (phenological) mismatch between production and consumption”

In the paper

“Geochemical impacts on biology via noxious gas, acidification, and lack of oxygen.”

In the paper

“Changes in composition or intensity of primary productivity, with direct trophic linkages to and subsequent changes in community composition of heterotrophs”

In the paper

“A possible tendency for increased coastal upwelling intensity as climate change proceeds could partially buffer coastal upwelling ecosystems from the increases in temperature and decreases in nutrient supply that may impact other types of regional-scale ocean ecosystems.”

In the paper

“Other more versatile components that may be less tied to predator-free shore zones might successfully exploit opportune ecological Bloopholes^that develop.”

In the paper

“Continental thermal lows are anticipated to deepen, which will intensify upwelling-favorable (equatorward) winds.”

In the paper

“Redistribution of populations through habitat changes”