NORTHWESTERN HAWAIIAN ISLANDS MAPPING

Mapping human impacts

K. Selkoe, Erik C. Franklin, and R. Toonen

Human impact maps, blue indicates low impact and red indicates high. * click image to see larger

Human impact maps, blue indicates low impact and red indicates high.

The human impacts mapping project has been developed to provide the Northwestern Hawaiian Islands (NWHI) user groups (managers, scientists, citizens), with an easy to use, coherent framework for viewing all types of spatial data and analyses on the current impacts of anthropogenic (human) threats. Frequency of thermal stress for the NWHI derived from satellite data of sea surface temperatures between 1985 and 2005 is one of the more exciting attributes included, because it allows the likelihood of coral bleaching and coral disease outbreaks to be mapped. These maps can be used to target areas for investigation of past or ongoing bleaching and disease similar to Kenyon and Brainard 2004. Another newly available dataset uses a spatial model of seawater acidification due to accelerating global carbon dioxide levels at one degree resolution created by John Guinotte. Other information in our atlas of threats includes shipping activity used to predict areas most affected by ship-based pollution, animal strikes and groundings, increased ultraviolet radiation from global climate change, marine debris data provided by the NOAA Fisheries Marine Debris Team, alien species establishment provided by Scott Godwin, past bottomfishing and lobster trapping activity, and research use.

All the data from these human threats were combined with habitat maps from the Biogeographic Assessment Team using a new technique developed by Halpern et al. (2007) to take variable expert opinions on various threats and make objective and repeatable predictions about how those threats impact marine ecosystems (Halpern et al. 2008). This technique was applied to the Hawaiian Archipelago to catalogue all relevant threats (Selkoe et al. 2008) and then to predict the ecological consequences of their spatial distribution on threat maps for the region (Selkoe et al. 2009). The results show that cumulative human impacts peaks at the middle of the archipelago, with as many as 11-13 overlapping threats occurring at sites at Maro Reef, Laysan and other shallow reef areas. Disease-related sea temperature change was found to be the worst threat, followed closely by sea water acidification. Sea level rise, ship based pollution and bottomfishing were relatively moderate, and marine debris and the 3 research threats had almost no relative impact compared to the others, although the marine debris dataset had many gaps and so impact is underestimated.

Recent papers related to this work

Guinotte JM, Buddemeier RW, Kleypas JA (2003) Future coral reef habitat marginality: temporal and spatial effects of climate change in the Pacific basin. Coral Reefs 22:551-558

Halpern BS, Selkoe KA, Walbridge S, Kappel CV, Micheli F, D’Agrosa C, Bruno JF, Casey KS, Ebert C, Fox HE, Fujita R, Heinemann D, Lenihan HS, Madin EP, Perry MT, Selig ER, Spalding M, Steneck R, Watson R. 2008. A global map of human impact on marine ecosystems. Science 319: 948-952.

Kenyon J, Brainard R (2006) Second recorded episode of mass coral bleaching in the Northwestern Hawaiian Islands. Atoll Research Bulletin 543:505-524

Selkoe, K.A., B.H. Halpern, C. Ebert, E. Franklin, E. Selig, K. Casey, J. Bruno, R.J. Toonen 2009 A map of cumulative impacts to a “pristine” coral reef ecosystem, the Papahānaumokuākea Marine National Monument.  Coral Reefs. In press. (doi:10.1007/s00338-009-0490-z)

Selkoe, K.A., B.S. Halpern & R.J. Toonen (2008) Evaluating and ranking the vulnerability of regions within the Papahānaumokuākea Marine National Monument to anthropogenic threats.  Aquatic Conservation: Marine and Freshwater Ecosystems 18: 1149-1165.

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