Shifting Baseline Syndrome Research Articles

European bison conservation cannot afford to ignore alternative hypotheses: a commentary on Perzanowski et al. (2019)

European bison conservation cannot afford to ignore alternative hypotheses: a commentary on Perzanowski <i>et al</i>. (2019)

Using historical information and data to strengthen planning for environmental protection and management at Everglades National Park, South Florida

The early environmental conditions in many national parks fit the favorable description given to Everglades National Park (ENP) at the time of its founding that the park’s wilderness and ecological resources were “superlative in value.” With the understanding that wilderness does not mean complete human exclusion, this study examines the possibilities, interests, and difficulties associated with establishing the historical superlative state of the park’s resources as a target for current restoration efforts. The focus is specifically on ENP, as the park’s existence was considered justified only if its superlative and pristine wilderness conditions could be retained in the future. Data were gathered from 18 historical documents obtained from the ENP museum and the online archives of the library shared by Florida International University and the University of Miami. The 1979 Master Plan, 2000 Comprehensive Everglades Restoration Plan (CERP) and other literature provided planning information. Qualitative data analysis was performed using NVivo 11. The findings indicate that the current restoration targets are heavily influenced by shifting baseline syndrome and that outcomes fall short of no net loss of environmental resources. Therefore, the restoration targets not based on the region’s resources during the predrainage period are technically achievable but cannot produce a restored ecosystem in the long term. This study concludes that that planning initiatives should go beyond pollution reduction strategies to include historical conditions and acquisitions of conservation lands as targets for ongoing restoration efforts.

Shifting baseline syndrome highlighted by anecdotal accounts from snapper (Ocyurus chrysurus) fishery

The fishes of the Lutjanidae family are widely distributed throughout the Atlantic, Indian and Pacific Oceans and have relevant commercial importance. Yellowtail snapper ( Ocyurus chrysurus ) is a targeted species in the small-scale fishery of the northeastern coast of Brazil, notably for hand-line fishing. We used the local ecological knowledge (LEK) of three generations of fishers from Ilheus (southern Bahia State, Brazil) to evaluate the perception of weight, best day of capture and relative abundance of the species. More experienced fishers captured the largest specimens, had larger catches and were more likely to indicate a decrease in species abundance. On the other hand, younger fishers had smaller catches and were more likely to indicate that the species abundance is stable or increasing. The results suggest the occurrence of shifting baseline syndrome among fishers and emphasize the importance of including information from fishers in the construction of management measures. Fishers can play a key role in developing viable proposals that are aimed at the management of fishing of species with spawning aggregation, such as yellowtail snapper.

Did a Shifting Ecological Baseline Mask the Predatory Effect of Striped Bass on Delta Smelt?

Author(s): Nobriga, Matthew L.; Smith, Wiliam E. | Abstract: Striped Bass, Morone saxatilis, has been an established member of the San Francisco Estuary’s (estuary’s) aquatic community for nearly a century and a half. As a predator, it has the potential to shape community composition through top-down control of lower trophic species, including the endangered Delta Smelt, Hypomesus transpacificus. Invasive predators can be particularly disruptive to native communities because they present novel dangers to naive populations, but, as a long-established member of the aquatic community, Striped Bass has not previously been considered to limit the Delta Smelt population. Here, we develop an argument that Striped Bass are important to controlling Delta Smelt. We support this argument by reviewing historical data which suggests that declines in Delta Smelt before the current-day monitoring program were driven by the invasion of Striped Bass into the estuary. We describe this phenomenon as the ‘phantom predator’ hypothesis in the context of an analog to the shifting baseline syndrome previously described for marine fisheries. A deeper understanding of how well studied (and rapidly changing) bottom-up drivers of the estuary food web interact with poorly understood (but also rapidly changing) controls at the top of the food web could prove very important to the conservation of other declining native fishes and possible future attempts to re-introduce captive-reared Delta Smelt to the estuary.

Use of historical data to assess changes in the vulnerability of sharks

Shark populations have declined worldwide. However, the lack of data for most species makes it difficult to use conventional population assessments to estimate their status. The productivity and susceptibility analysis (PSA) has been recommended for elasmobranchs as it is a data-poor assessment that uses the best available information of the species and their fisheries to determine their vulnerability. A historical characterisation was performed to define the most important periods for the shark fishery in Campeche, southern Gulf of Mexico, and a PSA was conducted to determine the vulnerability of the eleven most important commercial shark species in each three periods. The periods were defined as: local commercialisation (1940–1979), when all species had their lowest vulnerability values, and Carcharhinus leucas, Negraprion brevirostris, and Sphyrna mokarran were classified as highly vulnerable; developed industry (1980–1998) when there was an increase of the fishing pressure, and most small species changed from low to moderate vulnerability and the large coastal sharks scored their highest vulnerability values; and declining industry (1999–2018), when all species had lower vulnerability values than in the developed industry period. However, Carcharhinus brevipinna, Ginglymostoma cirratum, N. brevisrostris, C. leucas, and S. mokarran were still classified as highly vulnerable and could be suffering the accumulative effects of decades of fishing pressure. This multidisciplinary approach serves to identify the most vulnerable species throughout the history of the fishery and to understand the vulnerability values within a historical context, avoiding the shifting baseline syndrome.

Reconstructing the history of the sand tiger shark (Carcharias taurus) in the Mediterranean Sea

Abstract Sharks are globally exposed to several anthropogenic threats, which, in many cases, have severely reduced their distribution and have impacted populations. In the Mediterranean Sea, because of its long history of exploitation and the relatively short span of scientific monitoring, reconstructing shark baselines is challenging. Many vulnerable species declined in population abundance and geographic distribution before it was possible to adequately track these changes. Consequently, for many of these species, current conservation assessments are now suffering from a severe case of shifting baseline syndrome, whereby their historical occurrence in the area is questioned. The sand tiger shark (Carcharias taurus) is one of these cases. Characterized by high philopatry, restricted home range, and low interchange between populations, its Mediterranean population may have been severely impacted by the high historical fishing pressure in the region before scientific monitoring began. In this study, the history of the abundance and distribution of C. taurus in the Mediterranean Sea was reconstructed through a comprehensive search of occurrence records in the literature and in museum collections. Between 1810 and 2008, 31 occurrence records and 54 publications provided information on the presence of the species in the area. These records were sparse but systematic over time and indicated occurrence hot spots in the south‐western Mediterranean Sea and in the eastern Adriatic Sea. The presence of ten sightings of juveniles from a total of 18 sightings with length information suggested local parturition. Habitat and extinction models indicate that the area has suitable oceanographic conditions for the occurrence of the species and that the species cannot be considered extinct in the Mediterranean Sea. Our study suggests that there is still hope for the recovery of the species and underlines the crucial role of historical investigations to reconstruct the history of large elasmobranchs in the Mediterranean Sea.

“Seas of risk”: Assessing the threats to colonial-nesting seabirds in Eastern Canada

This study presents the results of the first broad-scale, spatial cumulative impact analysis (SCIA) conducted for colonial-nesting seabirds at-sea in eastern Canada. Species distribution models, based on at-sea tracking data for thirteen species/groups of seabirds (n = 520 individuals), were applied to over 5000 species-specific colonies to map relative abundance patterns across the entire region. This information was combined with distributional data for a number of key anthropogenic threats to quantify exposure to fisheries, light and ship-source oil pollution, and marine traffic. As a final step, information about species-specific sensitivity to each threat was integrated to compute region-wide cumulative risk.The data products permit the visualization of the interaction between species and threats, and confirm that large portions of the coastal zones of Nova Scotia and Newfoundland, as well as the Grand Banks shelf break, constitute areas where breeding seabirds experience the highest potential impact. The cumulative risk maps revealed that species which were either widespread throughout coastal areas (e.g., gulls), or capable of foraging long distance (Leach's Storm-Petrel), were most at risk. Cumulative risk maps help identify appropriate and potentially effective management and conservation actions, and are of value to federal regulators responsible for managing cumulative effects as part of the new Canadian Impact Assessment Act. They also can assist marine planners achieve the Aichi marine conservation targets as specified by the Convention on Biodiversity. By filling a knowledge gap for a large potion of the northwest Atlantic, these results help to counter the “shifting baselines syndrome”.

Choice of baseline affects historical population trends in hunted mammals of North America

Establishing historical baselines of species' populations is important for contextualising present-day population trends, identifying significant anthropogenic threats, and preventing a cultural phenomenon known as ‘shifting baseline syndrome’. However, our knowledge of historical baselines is limited by a lack of direct observation data on species abundance pre-1970. We present historical data of species-specific fur harvests from the Canadian government and Hudson's Bay Company as a proxy for estimating species abundance over multiple centuries. Using stochastic stock reduction analysis originally developed for marine species, we model historical population trends for eight mammals, and assess population trends based on two different baseline years: 1850 and 1970. Results show that population declines are significantly greater when using an 1850 baseline, as opposed to a 1970 baseline, and for four species, the population trend shifted from a population increase to a decrease. Overall, the median population change of the eight species changed from a 15% decline for 1850, to a 4% increase for 1970. This study shows the utility of harvest data for deriving population baselines for hunted terrestrial mammals which can be used in addition to other historical data such as local ecological knowledge. Results highlight the need for developing historically relevant population baselines in order to track abundances over time in threatened species and common species alike, to better inform species conservation programs, wildlife management plans and biodiversity indicators.

Long‐term changes in fishery resources of an estuary in southwestern Atlantic according to local ecological knowledge

AbstractLong‐term changes in the abundance of fisheries resources from the Patos Lagoon estuary and adjacent coastal waters in southern Brazil have been observed. Despite this understanding, it is well known that the perception of pristine state of the environment is susceptible to inter‐generational changes, commonly known as shifting baseline syndrome (SBS). An useful approach in the reconstruction of pristine scenarios and in lack of data, as often occurs in small‐scale fisheries, is the local ecological knowledge (LEK). Temporal changes in the perception of 81 fishers with 1–63 years of fishing about the resources status were analysed. More experienced fishers reported larger catches, heavier individuals and perceived a greater number of species as "scarce" nowadays and "common" at the beginning of their careers proving the existence of a SBS among them. Over time, the number of fishing sites with very high catches decreased and fishing sites shifted from the lower towards the upper estuary. The perception of the fishers corroborated the real decreasing scenario in estuarine fisheries resources shared with industrial fishing in coastal waters. The results reinforce the utility of LEK for reconstruction of biological scenarios when no empirically obtained data are available.

Tracking interactions: Shifting baseline and fisheries networks in the largest Southwestern Atlantic reef system

Abstract Increasing evidence has revealed that different fisheries have collapsed around the world. This is generally more evident in countries that can maintain long‐term research and fisheries monitoring. When monitoring data are not available, alternative approaches to assess fisheries trends can be used, such as the local ecological knowledge of fishers. To investigate decadal changes in fisheries the local ecological knowledge of small‐scale fishers' was evaluated at four sites in Brazil: Porto Seguro, Prado, Alcobaça, and Caravelas. A fisher–fish network weighted by interaction strength was built to indicate the most relevant resources among fishers. The results suggest the occurrence of the shifting baseline syndrome among generations of fishers regarding commercially important fishes such as groupers and snappers. Handline fishers indicated a decline in catch per unit effort over 5 decades. Fisher–fish networks from Caravelas showed greater stability with stronger interaction strength, while Porto Seguro and Alcobaça networks were more fragile, and Prado network showed intermediate characteristics. Overfishing has affected high trophic level species that act as module hubs across the majority of sites. The fisher–fish network approach can be applied in data limited cases, improving the assessments of fisheries' dynamics (in space and time) and declining species.

Shifting baselines in coral conservation

Reef-building corals are increasingly exposed to warming ocean temperatures. Their immediate response to this rise in temperature is to expel their symbiotic algae and turn white, or bleach. It is mainly for these reasons that corals have been perceived by scientists as both a sign and a measure of the imminent catastrophe facing life in the oceans and, subsequently, on earth. To measure coral decline across space and time, coral scientists have come up with maps, indexes, and color-coded representations. Yet they soon realized that what they regard as today’s healthy reef is, in fact, yesterday’s depleted reef. This problem, referred to as the shifting baselines syndrome, renders most comparisons across time difficult and frustrates the ability to predict the future. The problem is exacerbated in the context of oceans, and further yet in the context of coral reefs, because of the lack of reliable historical records. In fact, many of the coral scientists I have interviewed perceive shifting baselines as one of the key challenges facing coral conservation scientists and managers in their attempts to accurately calculate coral decline—a project that is typically deemed necessary for effective management policies and restoration practices. My article will critically explore the application of, and the assumptions behind, the shifting baselines concept in the context of reef coral science. Specifically, I will draw on interviews with coral scientists to describe the practices and devices embedded in the creation of baselines for corals and, finally, I will explore how certain scientists are challenging the conceptions of nature and time that underlie their operations.

Unshifting the baseline: a framework for documenting historical population changes and assessing long-term anthropogenic impacts.

Ecological baselines-reference states of species' distributions and abundances-are key to the scientific arguments underpinning many conservation and management interventions, as well as to the public support to such interventions. Yet societal as well as scientific perceptions of these baselines are often based on ecosystems that have been deeply transformed by human actions. Despite increased awareness about the pervasiveness and implications of this shifting baseline syndrome, ongoing global assessments of the state of biodiversity do not take into account the long-term, cumulative, anthropogenic impacts on biodiversity. Here, we propose a new framework for documenting such impacts, by classifying populations according to the extent to which they deviate from a baseline in the absence of human actions. We apply this framework to the bowhead whale (Balaena mysticetus) to illustrate how it can be used to assess populations with different geographies and timelines of known or suspected impacts. Through other examples, we discuss how the framework can be applied to populations for which there is a wide diversity of existing knowledge, by making the best use of the available ecological, historical and archaeological data. Combined across multiple populations, this framework provides a standard for assessing cumulative anthropogenic impacts on biodiversity. This article is part of a discussion meeting issue 'The past is a foreign country: how much can the fossil record actually inform conservation?'

Wild salmon and the shifting baseline syndrome: application of archival and contemporary redd counts to estimate historical Chinook salmon (Oncorhynchus tshawytscha) production potential in the central Idaho wilderness

The “shifting baseline syndrome” (SBS) is the paradigm whereby recent species abundances and environmental conditions are accepted as reflecting historical conditions. This leads to false impressions of the past, inaccurate baselines, and unrealistic recovery goals. Idaho biologists have counted Chinook salmon redds for &gt;60 consecutive years, generating an invaluable database; however, inaccurate historical baselines compromise the utility of even such high-quality, long-term databases. To develop an accurate baseline, we integrated archival (1951–1964), maximum redd counts with contemporary (1995–2017), continuous counts and spawn timing datasets to estimate historical (1950s–1960s) wild Chinook salmon production potential. Current salmon populations average 3% of 1950s–1960s abundances, which may have been 30% of precommercial fishery (1880s) populations. Notably, the SBS has influenced contemporary managers as reflected in minimum viable abundance, sustainable escapement, and adequate seeding objectives equaling 10.4%, 17.9%, and 20.4%, respectively, of 1950s–1960s potential. Our approach provides a framework for utilizing archival and contemporary data to reconstruct historical baselines and repress SBS. Contrasting contemporary goals with maximum production potential provides new reference points and perspectives for managers to consider.

Shifting baselines in a Mediterranean small-scale fishery

The overexploitation of marine resources has led to a decrease in species abundance over time in many marine ecosystems worldwide. But as new fishers arise throughout the years, the perception of local abundance changes which might result in a “shifting baselines syndrome”. We investigated how the perception of fishers about species abundance changed through time (from 1970 to 2016) and space (five ports), through questionnaires in the small-scale/artisanal fisheries of Murcia, Spain. Two major results emerged, firstly species catches significantly decreased between the decades 1970–1990 and 2000–2016, possibly due to overfishing and habitat degradation. Catches of species with some particular functional traits decreased (96%) possibly due to lower plasticity or to a “fishing down the food web” effect. Secondly, some functional trait categories (very large size, deep water depth, large yearly displacements and very vagile) were the highest in the northern ports of San Pedro del Pinatar and Cartagena while Cabo de Palos had the highest values in species with solitary and territorial behaviour and vagile or sedentary mobility. Fishers’ perception of catch trends of commercial species seemed aligned with other sources of information for this area and might be key information in the absence of more quantitative information.

A method to estimate pre‐exploitation population size

Antarctic fur seals (Arctocephalus gazella) were commercially exploited on the subantarctic island of South Georgia for over 100 years and nearly driven to extinction. Since the cessation of harvesting, however, their populations have rebounded, and they are now often considered a nuisance species whose impact on the terrestrial landscape should be mitigated. Any evaluation of their current population requires the context provided by their historic, pre-exploitation abundance, lest ecologists fall prey to shifting baseline syndrome in which their perspective on current abundance is compared only with an altered state resulting from past anthropogenic disturbance. Estimating pre-exploitation abundance is critical to defining species recovery and setting recovery targets, both of which are needed for the International Union for the Conservation of Nature's recent efforts to develop a green list of recovering species. To address this issue, we reconstructed the South Georgia fur seal harvest from 1786 to 1908 from ship logbooks and other historical records and interpolated missing harvest data as necessary with a generalized linear model fit to the historical record. Using an approximate Bayesian computation framework, harvest data, and a stochastic age-structured population model, we estimated the pre-exploitation abundance of Antarctic fur seals on South Georgia was 2.5 million females (95% CI 1.5-3.5 million). This estimate is similar to recent abundance estimates, and suggests current populations, and the ecological consequences of so many fur seals on the island, may be similar to conditions prior to human harvest. Although the historic archive on the fur sealing era is unavoidably patchy, the use of archival records is essential for reconstructing the past and, correspondingly, to understanding the present. Article impact statement: Defining species recovery requires an understanding of baseline population state, which can be estimated through statistical methods.

Shifting Gears for the Use of the Shifting Baseline Syndrome in Ecological Restoration

There are two barriers to accomplishing restoration of ecosystems: insufficient information about historical baselines to guide restoration, and shifts between the actual baselines and perceptions about historical conditions. These two conditions generate a phenomenon called shifting baseline syndrome (SBS). Our study systematically reviewed and quantitatively analyzed the SBS studies. There is an increase and subsequent stabilization in the number of publications, 32% of scientific articles added new information and 5% of them delivered biological and social information required to demonstrate the SBS presence. Meta-analysis conducted showed an inconsistency between biological and social data. The inclusion of a greater amount of species in the biological data compared to social data produced the inconsistency. There must be an improvement in reporting both biological and social information to assess SBS. The integration of both sources of information would also enhance the success of restoration projects. The consideration of perceptions about resource users are also in accordance with global agreements about sustainable use of natural resources and ecological restoration.

Shifting headlines? Size trends of newsworthy fishes.

The shifting baseline syndrome describes a gradual lowering of human cognitive baselines, as each generation accepts a lower standard of resource abundance or size as the new norm. There is strong empirical evidence of declining trends of abundance and body sizes of marine fish species reported from docks and markets. We asked whether these widespread trends in shrinking marine fish are detectable in popular English-language media, or whether news writers, like many marine stakeholders, are captive to shifting baselines. We collected 266 English-language news articles, printed between 1869 and 2015, which featured headlines that used a superlative adjective, such as ‘giant’, ‘huge’, or ‘monster’, to describe an individual fish caught. We combined the reported sizes of the captured fish with information on maximum species-specific recorded sizes to reconstruct trends of relative size (reported size divided by maximum size) of newsworthy fishes over time. We found some evidence of a shifting baseline syndrome in news media over the last 140 years: overall, the relative length of the largest fish worthy of a headline has declined over time. This pattern held for charismatic fish species (e.g. basking sharks, whale sharks, giant mantas), which are now reported in the media at smaller relative lengths than they were near the turn of the 20th century, and for the largest species under high risk of extinction. In contrast, there was no similar trend for pelagic gamefish and oceanic sharks, or for species under lower risk of extinction. While landing any individual of the large-bodied ‘megafish’ may be newsworthy in part because of their large size relative to other fish species, the ‘megafish’ covered in our dataset were small relative to their own species—on average only 56% of the species-specific maximum length. The continued use in the English-language media of superlatives to describe fish that are now a fraction of the maximum size they could reach, or a fraction of the size they used to be, does reflect a shifting baseline for some species. Given that media outlets are a powerful tool for shaping public perception and awareness of environmental issues, there is a real concern that such stories might be interpreted as meaning that superlatively large fish still abound.

Indigenous knowledge as a remedy for shifting baseline syndrome

Soga and Gaston (2018) recently outlined the features of shifting baseline syndrome (SBS; Pauly 1995), a condition whereby each new generation inherits an environment that has worsened from the generation before, producing lowered expectations for conservation and restoration. They showed some of the self‐reinforcing elements of SBS and provided four recommendations to help counter it: (1) restore the natural environment, (2) monitor and collect data, (3) reduce the extinction of experience, and (4) educate the public. I commend the authors for clearly articulating this syndrome and offering potential paths forward to correct it. Across a spectrum of environmental domains, SBS is pervasive, and many of its most pressing challenges are concentrated in remote sections of the Tropics and the Arctic, regions that to outsiders may appear relatively untouched by human activities. Here I argue that Indigenous knowledge (IK) has a strong role to play in limiting the shifting of baselines, especially in countering perceptions of these regions as pristine environments. IK, also referred to as traditional (ecological) knowledge, has been defined as “a cumulative body of knowledge, practice and belief, evolving by adaptive processes and handed down through generations by cultural transmission, about the relationship of living beings (including humans) with one another and with their environment” (Berkes 2008). Notably, IK has the potential to advance a narrative of past environmental conditions, an appropriate baseline against which to judge current state.

For generations to come? The privatization paradigm and shifting social baselines in Kodiak, Alaska's commercial fisheries

This paper presents results from a study that explored a key threat to fisheries sustainability in Alaska – the graying of the commercial fishing fleet. In the Kodiak Archipelago region this research utilized a political ecology framework and mixed methods ethnography, including 70 semi-structured interviews and participant observation, to further understand this problem. Study results suggest that opportunities for young rural fishermen are increasingly constrained by interrelated socioeconomic and cultural barriers, which have created systemic equity and sustainability concerns. Furthermore, research indicates that the privatization paradigm of fisheries access is a major catalyst of change that has created and amplified barriers, transformed opportunity, and generated lasting inequities and social conflict. Foucault's concept of governmentality is used to describe how some fishermen are internalizing and normalizing privatization discourses to advance further regulatory change. Pauly's concept of shifting baseline syndrome is evoked to argue that current structures of degraded access and equity in the human fishery system are mistakenly assumed to be a natural state, rather than a result of a specific history of public policy choices. Due to the suite of challenges facing fishing people and communities, it is increasingly important to acknowledge the privatization of access as a key threat to sustainable coastal fishing futures.

Shifting baseline syndrome: causes, consequences, and implications

With ongoing environmental degradation at local, regional, and global scales, people's accepted thresholds for environmental conditions are continually being lowered. In the absence of past information or experience with historical conditions, members of each new generation accept the situation in which they were raised as being normal. This psychological and sociological phenomenon is termed shifting baseline syndrome (SBS), which is increasingly recognized as one of the fundamental obstacles to addressing a wide range of today's global environmental issues. Yet our understanding of this phenomenon remains incomplete. We provide an overview of the nature and extent of SBS and propose a conceptual framework for understanding its causes, consequences, and implications. We suggest that there are several self‐reinforcing feedback loops that allow the consequences of SBS to further accelerate SBS through progressive environmental degradation. Such negative implications highlight the urgent need to dedicate considerable effort to preventing and ultimately reversing SBS.