Adaptive governance and the human dimensions of marine mammal management: Implications for policy in a changing North

As climate change has driven dramatic changes in Northern sea ice regimes, marine mammals have gained iconic status around the world reflecting the perils of global warming. There is a tension between policies that have international support like a ban on seal hunting or whaling, and the adoption of adaptive, flexible rules that are likely to work in Northern places. Whereas most wildlife policy focuses on biological information to inform policy strategy, this analysis focuses on the “human dimensions” of Northern marine mammal management. This research examines ways in which human relationships and modes of governance affect conservation success. Standard analyses of risk to animal populations focused on direct sources of take are inadequate to address multi-causal, complex problems such as climate-induced habitat loss or increased industrialization of the Arctic Ocean. Early conservation policy strategies focusing on the moratorium of take have eliminated or reduced such practices as commercialized hunting and high levels of fisheries bycatch, but may be less relevant in an era in which habitats and climate changes are key drivers of population dynamics. This paper argues that effective adaptive policy requires new ways of learning about and governing human interactions with marine mammals. Through an exploration of marine mammal management in three Northern regions (Alaska, Nunavut, and the Finnish Baltic Sea coast), the paper analyzes the extent to which these marine mammal management regimes are practicing adaptive governance, that is, building cross-scale (local to international) understanding while allowing actors at the local scale the flexibility to direct the creation of rules that are ecologically robust and likely to succeed. Lessons are taken from these examples and used to propose selected policy and research recommendations for the marine mammal policy community.     

The human dimensions of marine mammal management in a time of rapid change: comparing policies in Canada,Finland and the United States

Arctic coastal populations share a close relationship with their environment consisting of linkages among communities, landscapes and seascapes, and the social institutions developed to sustain the system. This cultural–biogeophysical dynamic is termed throughout the section as a social–ecological system (SES). Marine mammals constitute a large portion of the subsistence diet for these communities, and as such represent key ecological services provided by the system. At the same time, marine mammals have gained iconic status as symbols for climate change in the North. A tension results between the demands of balancing on one hand good policy optics consistent with national and international norms and, on the other hand, flexible and adaptive institutions able to take on the task of managing resources in a dynamic, changing North. This tension and associated policy solutions such as co-management are explored in a series of papers focusing on marine mammal management dilemmas and policy practices around the circumpolar North. This introduction communicates the problem context and describes the five papers making up this special section. A guiding premise to this work is that new international pressures to implement moratoria on marine mammal hunting in the North ignore critical human dimensions of marine mammal management. Such policy proposals are unlikely to succeed in areas that require collaboration across scales. Simultaneously, new local-scale participation in multi-level management regimes holds promise for creating more resilient marine mammal SESs.     

High thresholds for avoidance of sonar by free-ranging long-finned pilot whales (Globicephala melas)

The potential effects of exposing marine mammals to military sonar is a current concern. Dose–response relationships are useful for predicting potential environmental impacts of specific operations. To reveal behavioral response thresholds of exposure to sonar, we conducted 18 exposure/control approaches to 6 long-finned pilot whales. Source level and proximity of sonar transmitting one of two frequency bands (1–2 kHz and 6–7 kHz) were increased during exposure sessions. The 2-dimensional movement tracks were analyzed using a changepoint method to identify the avoidance response thresholds which were used to estimate dose–response relationships. No support for an effect of sonar frequency or previous exposures on the probability of response was found. Estimated response thresholds at which 50% of population show avoidance (SPL_max = 170 dB re 1 μPa, SEL_cum = 173 dB re 1 μPa² s) were higher than previously found for other cetaceans. The US Navy currently uses a generic dose–response relationship to predict the responses of cetaceans to naval active sonar, which has been found to underestimate behavioural impacts on killer whales and beaked whales. The navy curve appears to match more closely our results with long-finned pilot whales, though it might underestimate the probability of avoidance for pilot-whales at long distances from sonar sources.     

Modelling exposure of oceanic higher trophic-level consumers to polychlorinated biphenyls: Pollution ‘hotspots’ in relation to mass mortality events of marine mammals

Marine mammals in the past mass mortality events may have been susceptible to infection because their immune systems were suppressed through the bioaccumulation of environmental pollutants such as polychlorinated biphenyls (PCBs). We compiled mortality event data sets of 33 marine mammal species, and employed a Finely-Advanced Transboundary Environmental model (FATE) to model the exposure of the global fish community to PCB congeners, in order to define critical exposure levels (CELs) of PCBs above which mass mortality events are likely to occur. Our modelling approach enabled us to describe the mass mortality events in the context of exposure of higher-trophic consumers to PCBs and to identify marine pollution ‘hotspots’ such as the Mediterranean Sea and north-western European coasts. We demonstrated that the CELs can be applied to quantify a chemical pollution Planetary Boundary, under which a safe operating space for marine mammals and humanity can exist.     

Managing U.S. Atlantic large whale entanglements: Four guiding principles

Fatal entanglements in fishing gear threaten marine mammal populations worldwide. The management of entanglements of large whales, such as the North Atlantic right whale (Eubalaena glacialis), with commercial fisheries, is a challenge given the species’ small population size, economic consequences of regulations, and the general lack of data on entanglements. The U.S. Marine Mammal Protection Act (MMPA) requires development of programs to limit marine mammal entanglement in commercial fishing gear. Following a retrospective look at implementing aspects of the MMPA, a set of guiding principles were developed with associated best practices useful in reducing fatal large whale entanglement in fishing gear. Among these are: 1) involve stakeholders early in the decision making process; 2) establish a transparent management strategy that includes critical needs to guide research; 3) use a variety of tools such as an established process for receiving new information and ideas; and 4) incorporate adaptive management which considers the constraints of dynamic (rapid) changes to some fixed fishing gear. Efforts to reduce worldwide marine mammal bycatch will typically occur in a data-limited environment as experienced with U.S. Atlantic large whale entanglements. The guiding principles will remain as key tools for reducing large whale bycatch in fisheries as they build upon common practices. These insights developed over two decades of management can potentially help others to address similar bycatch problems.     

Opportunities for improving global marine conservation through multilateral treaties

The speed and scale of human impacts on marine species, such as climate change and exploitation for international markets, coupled with a poor regulatory regime and lack of enforcement, make it especially difficult to protect marine species beyond areas of national jurisdiction. Yet as the number of multilateral treaties continues to grow, the declining state of the world's oceans suggest that these treaties are largely failing to fulfill their missions and achieve meaningful protection. Here, an analysis of all multilateral treaties governing activities related to oceans is provided. A range of issues is examined including efficacy, geographic and taxonomic distribution, and other factors that facilitate or inhibit conservation. Since 1882, 103 countries have signed 265 multilateral treaties related to the management of marine resources. The majority of treaties (51%) deal with fisheries, 30% deal with pollution, 4% marine mammals and 15% deal with other topics. In terms of factors that may predict efficacy, 65% of marine treaties have secretariats, 50% have scientific mandates, and 13% have enforcement mechanisms; only 9% have all three. Given the context of the United Nations General Assembly's new commitment to manage human activity and its impact on common resources on the high seas, it is important to understand the strengths and weaknesses – individually and cumulatively - of existing binding marine agreements.     

Soil water condition and small mammal spatial distribution in Inner Mongolian steppes, China

We studied the roles of soil moisture contents and vegetation structure in the spatial distribution of small mammals in the typical steppes of Inner Mongolia, China, using logistic and linear regressions of a data set collected in a 6-year study. Our results indicated that soil moisture contents remained in the most parsimonious models for Spermophilus dauricus, Cricetulus barabensis, Microtus maximowiczii, M. gregalis, and Ochotona daurica. The relative abundance of C. barabensis, M. maximowiczii, and O. daurica was inversely related to soil moisture contents, while that of M. gregalis and S. dauricus was positively related to soil moisture contents in logistic regressions. Linear regression analyses showed that soil moisture contents and the number of small mammal species were inversely related. The negative effects of wet soil were consistent at both small mammal population and community levels in the semi-arid steppes. Above-ground plant biomass and plant coverage also affected the spatial distribution of small mammals in the typical steppe of Inner Mongolia.     

A new middle to late Eocene continental chronostratigraphy from NE Spain

The calibration of the European Paleogene mammal biochronology with the international reference geochronological scale is unconstrained due to the lack of direct marine-continental correlations and insufficient robust magnetostratigraphic data for mammal fossil-bearing sequences. The currently accepted European continental biochronology argues for a correlation of the Paleogene MP14 to MP16 mammal reference levels with the Bartonian stage, and of the MP17 to MP20 levels with the Priabonian. However, new magnetostratigraphic data of the continental sediments of the south-central Pyrenees substantially challenge this chronology. Our new results from the La Pobla de Segur Basin and Sierra de Sis have been integrated into the framework of previous marine-continental stratigraphic correlations and magnetostratigraphic data of the south-central Pyrenees. In this new chronology, MP14 and MP15 reference levels correspond to the Lutetian, whereas MP16 and early MP17 correlate with the early Bartonian. This calibration represents a significant revision of currently accepted marine-continental correlations in Europe, but is not in conflict with the available biostratigraphic data of the south Pyrenean Ebro foreland basin and other western European reference basins.     

Summary of taxa and distribution of Sirenia in the North Pacific Ocean

Abstract North Pacific fossil sirenians comprise representatives of three subfamilies of the Dugongidae: Halitheriinae ( Metaxytherium arctodites , Middle Miocene, North America), Hy-drodamalinae ( Dusisiren spp., Early-Late Miocene, and Hydrodamalis spp., Late Miocene-Pleistocene, North America and Japan), and Dugonginae ( Dioplotherium allisoni , Early-Middle Miocene, North America). Indeterminate dugongid remains are also known from the Late Oligocene of Japan, and the discovery of additional taxa in the western Pacific, especially in Paleogene rocks, can be anticipated. The known North Pacific Neogene taxa apparently dispersed into the Pacific from the Caribbean. Metaxytherium gave rise in the Pacific to Dusisiren ; a series of chronospecies of the latter genus eventually culminated in Hydrodamalis , which was exterminated by humans circa AD 1768. Dioplotherium left no known descendants in the Pacific. The Recent Dugong probably entered the Pacific from the Indian Ocean. The presence in the North Pacific Miocene of at least three sympatric dugongid lineages, together with desmostylians, is evidence for a diversity of marine plants that was reduced by subsequent climatic cooling.     

Paleoenvironmental reconstruction of the coastal Monte Léon and Santa Cruz formations (Early Miocene) at Rincón del Buque,Southern Patagonia: A revisited locality

Sedimentological, ichnological and paleontological analyses of the Early Miocene uppermost Monte León Formation and the lower part of the Santa Cruz Formation were carried out in Rincón del Buque (RDB), a fossiliferous locality north of Río Coyle in Santa Cruz Province, Patagonia, Argentina. This locality is of special importance because it contains the basal contact between the Monte Léon (MLF) and the Santa Cruz (SCF) formations and because it preserves a rich fossil assemblage of marine invertebrates and marine trace fossils, and terrestrial vertebrates and plants, which has not been extensively studied. A ∼90 m-thick section of the MLF and the SCF that crops out at RDB was selected for this study. Eleven facies associations (FA) are described, which are, from base to top: subtidal–intertidal deposits with Crassotrea orbignyi and bioturbation of the Skolithos-Cruziana ichnofacies (FA1); tidal creek deposits with terrestrial fossil mammals and Ophiomorpha isp. burrows (FA2); tidal flat deposits with Glossifungites ichnofacies (FA3); deposits of tidal channels (FA4) and tidal sand flats (FA5) both with and impoverish Skolithos ichnofacies associated; marsh deposits (FA6); tidal point bar deposits recording a depauperate mixture of both the Skolithos and Cruziana ichnofacies (FA7); fluvial channel deposits (FA8); fluvial point bar deposits (FA9); floodplain deposits (FA10); and pyroclastic and volcaniclastic deposits of the floodplain where terrestrial fossil mammal remains occur (FA11).The transition of the MLF–SCF at RDB reflects a changing depositional environment from the outer part of an estuary (FA1) through the central (FA2–6) to inner part of a tide-dominated estuary (FA7). Finally a fluvial system occurs with single channels of relatively low energy and low sinuosity enclosed by a broad, low-energy floodplain dominated by partially edaphized ash-fall, sheet-flood, and overbank deposits (FA8–11). Pyroclastic and volcaniclastic materials throughout the succession must have been deposited as ash-fall distal facies in a fluvial setting and also were carried by fluvial streams and redeposited in both estuarine and fluvial settings. These materials preserve most of the analyzed terrestrial fossil mammals that characterize the Santacrucian age of the RDB's succession. Episodic sedimentation under volcanic influence, high sedimentation rates and a relatively warm and seasonal climate are inferred for the MLF and SCF section.Lateral continuity of the marker horizons at RDB serve for correlation with other coastal localities such as the lower part of the coastal SCF south of Río Coyle (∼17.6–17.4 Ma) belonging to the Estancia La Costa Member of the SCF.