S.K. Papworth, Rist J., CoadL., and Milner-Gulland E.J. 2009. Ecology and Organismal Biology. 2:2: 93 http://onlinelibrary.wiley.com/doi/10.1111/j.1755-263X.2009.00049.x/abstract

• Shifting baseline syndrome (SBS) is often referred to as a key issue for conservation, yet there is little evidence for its existence. The presence of SBS could influence the validity of participatory monitoring, local ecological knowledge, community based conservation, and conservation education. We outline two forms of SBS: (1) generational amnesia, where knowledge extinction occurs because younger generations are not aware of past biological con2009ditions and (2) personal amnesia, where knowledge extinction occurs as individuals forget their own experience. Two conditions are essential to the identification of SBS: (1) biological change must be present in the system and (2) any perceived changes must be consistent with the biological data. If age or experience-related differences in perception are then found, generational amnesia may be occurring. Alternately, if individuals believe current conditions also occurred in the past, personal amnesia may be occurring. Previous studies have not fully addressed these conditions, and hence cannot provide indisputable evidence for the existence of SBS. We present three case studies to examine these issues, which demonstrate both forms of SBS. Shifting baseline syndrome is no longer a cautionary tale, but instead is a real problem for those using human perceptions of change to inform conservation policy-making or management.

Jeremy B.C. Jackson and Nancy Knowlton. 2008. Shifting baselines, local impacts, and global change on coral reefs. PLoS Biology. 6.2: 215. http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.0060054

• This paper gives a broad overview of shifting baselines on coral reefs. Areas adjacent to coral reefs with high human populations typically impose more human-induced stressors on reef communities. These stressors, like overfishing and pollution, make it harder for coral reefs and associated species to withstand negative physical or biological factors, like changes in temperature, salinity, predators, or invasive species. Apex predators are of the biggest concern, since they are being overfished in many reef habitats and surrounding areas.

http://www.tcpalm.com/news/2012/may/29/historical-vignettes-of-martin-county-salerno-shar/

• Where have all our sharks gone? A historic shark fishery in Salerno, Florida gives insight into past abundance of sharks and the drastic declines that we are seeing today. To supply the growing demand for shark liver oil, sharks’ teeth, and “shark meal,” the Port Salerno Shark Factory “employed as many as 50 people and used 12 boats to haul in the 'tigers of the sea' some 25,000 or more per year.” Now these sharks are rare, suggesting that even local fishing by one small fishing village has the capacity to decimate an entire shark population in a matter of decades.

S. A. Sandin et al., Baselines and Degradation of Coral Reefs in the Northern Line Islands. PLoS ONE 3, e1548 (2008). http://www.plosone.org/article/info:doi%2F10.1371%2Fjournal.pone.0001548

• Establishing baselines of ocean health are important in determining effective management. Looking at adjacent reefs in the Northern Line Islands, Sandin and colleagues found that sharks were virtually absent on the more populated islands, while the majority of top predator biomass were sharks on the more pristine islands with no humans. The authors concluded that protected reefs with a higher biomass of top predators, like sharks, are more resilient to disturbances like coral bleaching that result from global warming.

M.R. Heithaus, Burkholder, D., Hueter, R.E., Heithaus, L.I., Pratt, Jr., H.L., and Carrier, J.C. 2007.  Spatial and temporal variation in shark communities of the lower Florida Keys and evidence for historical population declines. Canadian Journal of Fisheries and Aquatic Sciences, 64: 1302-1313.

• Historic accounts of a shark fishery in the Florida Keys suggest the depletion of shark populations at Heithaus and colleagues’ study site. This lead them to conclude “ecosystem impacts of changes in the large shark community may be dramatic and likely occurred before adequate baselines were established.”

Baum, J.K. & Myers, R.A. (2004). Shifting baselines and the decline of pelagic sharks in the Gulf of Mexico. Ecol. Lett., 7, 135–145.

• Baum and Myers compare historic and recent catch rate data to estimate regional shark declines in the Gulf of Mexico. Due to their vulnerable life history characteristics, sharks are extremely vulnerable to any exploitation. Baum and Myers state their “analysis provides the missing baseline for pelagic sharks in the Gulf of Mexico that is needed for the rational management and restoration of these species.”

Ecological extinction and evolution in the brave new ocean. Jeremy B. C. Jackson

• Jackson provides an overview of the global patterns of marine species exploitation. He illustrates the problems facing each major ocean realm and lists the percent decline for plant and animal species from various marine ecosystems. Jackson and colleagues have shown that many coastal and pelagic shark species have shown dramatic declines, some reduced up to 99% in particular regions.

Cascading Effects of the Loss of Apex Predatory Sharks from a Coastal Ocean. Ransom A. Myers, Julia K. Baum, Travis D. Shepherd, Sean P. Powers, Charles H. Peterson. 2007. VOL 315. SCIENCE. www.sciencemag.org http://www.sciencemag.org/content/315/5820/1846.short

• Drastic declines in top predatory sharks have had cascading effects, leading to the decline of a 100-year-old scallop fishery in the northwest Atlantic.

How severe are shark population decreases, and how do we know? By WhySharksMatter, on April 19th, 2012 http://www.southernfriedscience.com/?p=12947

• It is impossible to know exactly how many sharks there are in the ocean; however, there are several ways to estimate population trends of sharks. This is a review of those methods and supporting literature

An open letter concerning the unsustainability of shark finning. White Shark Conservation Trust. 29. May 2012 http://sharkyear.com/2012/an-open-letter-concerning-the-unsustainability-of-shark-finning.html#.T8s-IZWSPY8.facebook

• The shark fin trade is not sustainable. There is an abundance of scientific evidence that many shark populations are in decline, and a lack of adequate management and protection for these species. International shark experts call for urgent attention and action, in order to curb these declines and strengthen marine ecosystem integrity.

Shifting Baselines - How Can We Protect The Future Of The Oceans If We Don’t Know The Past? Randy Olson, 2006 http://www.patagonia.com/us/patagonia.go?assetid=8295

• ‘Shifting baselines’ is a term coined in 1995 that refers to the fact that “we assume that the way we see the world is the way it’s always been.” Unfortunately, we do not know historic state of our world and resources, so we do not know what we are missing. However, scientific studies that compare nearby atolls with varying levels of human disturbance give insight into the way the world used to be.

Stallings C (2009) Fishery-independent data reveal negative effect of human population density on Caribbean predatory fish communities. Plos One 4: e5333.

http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0005333?__utma=25604130.1276272835.1339104121.1339104121.1339171208.2&__utmb=25604130.7.10.1339171208&__utmc=25604130&__utmx=-&__utmz=25604130.1339104121.1.1.utmcsr=google|utmccn=%28organic%29|utmcmd=organic|utmctr=%28not%20provided%29&__utmv=-&__utmk=237423427

C. A. M. Ward-Paige, C.; Lotze, H. K.; Pattengill-Semmens, C.;, L. A.-C. McClenachan, E.; Myers, R. A. , Large-Scale Absence of Sharks on Reefs in the Greater- Caribbean: A Footprint of Human Pressures. PLoS ONE 5,  (2010).

http://www.plosone.org/article/info:doi%2F10.1371%2Fjournal.pone.0011968

C. A. a. L. Ward-Paige, Heike K. , Assessing the Value of Recreational Divers for Censusing Elasmobranchs. PLoS ONE 6,  (2011).

http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0025609