J. Limnol., 2014; 73(s1): 120-131 DOI: 10.4081/jlimnol.2014.795 Biological conservation of aquatic inland habitats: these are better days Ian J. WInfIeld* lake ecosystems Group, Centre for ecology & Hydrology, lancaster environment Centre, library Avenue, Bailrigg, lancaster, lA1 4AP, UK *Corresponding author: [email protected] ABSTRACT The biodiversity of aquatic inland habitats currently faces unprecedented threats from human activities. At the same time, although much is known about the functioning of freshwater ecosystems the successful transfer of such knowledge to practical conservation has not been universal. This alarming situation is considered here using a theme of the conservation of freshwater fishes, supported where appropriate with examples drawn from other taxa. Global awareness of aquatic conservation issues is also hampered by conditions under the water surface being largely hidden from the direct experience of most members of society. Connectivity, or lack of it, is another challenge to the conservation of freshwater habitats, while urban areas can play a perhaps unexpectedly important positive role. Fresh- water habitats frequently enjoy benefits accruing from a sense of ownership or stewardship by local inhabitants, which has led to the development of conservation movements which commonly started life centred on the habitat itself but of which many have now matured into wider catchment-based conservation programmes. A demonstrable need for evidence-based conservationonly management in turn re- quires scientific assessments to be increasingly robust and standardised, while at the same time remaining open to the adoption of tech- nological advances and welcoming the rapidly developing citizen science movement. There is evidence of real progress in this context and conservation scientists are now communicating their findings to environmental managers in a way and on a scale that was rarely seen a couple of decades ago. It is only in this way that scientific knowledge can be efficientlyuse transferred to conservation planning, prioritisation and ultimately management in an increasingly scaled-up, joined-up and resource-limited world. The principle of ‘pre- vention is better than cure’ is particularly appropriate to most biological conservation issues in aquatic inland habitats and is inextricably linked to educating and/or nudging appropriate human behaviours. When prevention fails, some form of emergency rescue such as cap- tive breeding or translocations may be justified for particularly important animal or plant populations. However, long-haul missions of habitat rehabilitation or restoration are generally to be preferred even if they may take decades to reach fruition. Conservation re- searchers, managers and practitioners must be realistic in their objectives and timescales for such programmes and take positive steps to communicate such information to stakeholders. Now more than ever, people are interested in conservation and sustainability. There are substantial challenges ahead, but these are better days for the biological conservation of aquatic inland habitats. Key words: biodiversity, citizen science, evidence-based, freshwater fish, knowledge transfer, standardised assessment. Received: May 2013. Accepted: July 2013. INTRODUCTION water ecosystems around the world. Such understanding should in principle aid our wise and sustainable manage- In december 2003, the UnitedNon-commercial nations General As- sembly proclaimed the years 2005 to 2015 to be an Inter- ment of these precious areas. However, dudgeon et al. national decade for Action on the specific theme of Water (2006) and many others have observed that the transfer of for Life (dudgeon et al., 2006). While the major actions such knowledge to the practical conservation of freshwa- aspired to within this resolution are concerned primarily ter biodiversity has been largely unsuccessful, due in part with development efforts such as the provision of safe to the special features of freshwater habitats that make drinking water and basic sanitation, dudgeon et al. (2006) them especially vulnerable to human activities. Indeed, in argued that these important matters should not obscure rapidly developing areas of the world, such as parts of the fact that this resolution comes at a time when the bio- Asia, some have even asked if inland aquatic biodiversity diversity and biological resources of inland waters are fac- has a future (Gopal, 2005). furthermore, although envi- ing unprecedented and growing threats from human ronmental issues including the conservation of freshwater activities. As we approach the end of this International biodiversity have benefitted from a heightened interest decade for Action, the biological conservation of aquatic from society over recent decades, a recent analysis of in- inland habitats continues to face intense challenges. As ternet search patterns suggests that some of this interest evidenced by other articles in this special volume, the in- may now be declining (McCallum and Bury, 2013). If ac- ternational research community now knows a great deal tually so, this is a negative development of great concern. about the functioning of both natural and perturbed fresh- As a result of the above trends, scientific research is I.J. Winfield 121 now needed more than ever to guide the conservation of through a variety of novel means around the world includ- the world’s aquatic inland habitats. Such conservation-led ing the active engagement of zoological societies and the research must be conducted alongside work addressing so- general public (McGregor Reid, 2013). The conservation ciety’s other needs and so should be undertaken with a pos- of freshwater fishes of aquatic inland habitats thus has a itive, pragmatic approach. In this context, it is notable that wealth of experiences, both negative and positive, from a recent review by Brown et al. (2010) of priority water re- which the wider conservation of aquatic inland habitats search identified by U.K. practitioners and policy makers may derive benefit. identified 94 questions on nine themes, including freshwa- ter biodiversity, communicating water research, and inte- SINGLE AND SYNERGISTIC THREATS grated catchment management. freshwater science and dudgeon et al. (2006) include an extensive review of particularly the ability to translate research into practice the threats facing freshwater biodiversity and group them also appeared in a recent list of most wanted skills in the under the five interacting categories of overexploitation, U.K. environment sector (lWeC, 2012). The persistent water pollution, flow modification, destruction or degra- messages from these and similar reviews are that the global dation of habitat, and invasion by exotic species (fig. 1). conservation of freshwater biodiversity must evolve to op- environmental changes occurring at larger spatial scales, erate realistically in a complex world, often alongside com- such as climate change or nitrogen deposition, are super- peting objectives, and that environmental researchers must imposed on all of these major threat categories and may increase their efforts to transfer their scientific understand- significantly influence their outcomes. Thus, even long- ing to the benefit of environmental managers. established environmentalonly threats to aquatic inland habi- Here, some personal observations are offered on the tats such as acidification and eutrophication, which as nature and practice of conservation science as it relates to single issues are now well understood and generally man- aquatic inland habitats. no attempt is made to produce a ageable given appropriate resources, now commonly op- comprehensive review of this large and complex subject, erate onuse habitats also subjected to additional pressures but rather consideration is focused on how such conser- such as changed flow patterns or higher temperatures. vation may be best achieved in what is usually a highly This results in impacts of potentially higher magnitudes diverse and multi-use environment. These observations and complexities. are approached using a theme of freshwater fishes and Such synergistic effects of multiple single threats are cover considerations of the single and synergistic threats rapidly becoming appreciated for a range of biota, with facing aquatic inland habitats, some notable features of for example the complicating effects of climate change the latter in the context of conservation, their assessment apparent for a range of aquatic organisms from macro- and finally their management. The challenges are un- phytes (Alahuhta et al., 2011) to fish (Jeppesen et al., doubtedly great, but it is argued that a number of recent 2012). Issues of habitat connectivity are paramount in developments give cause for optimism. many fresh waters as considered below, so it is unsurpris- ing that invasions by exotic species including the syner- A THEME OF FRESHWATER FISHES gistic influences of factors such as eutrophication, climate Any personal observations are of course likely to be change and flow modification are a major issue around both consciously and subconsciously influenced by the the world (dunham et al., 2002; Kats and ferrer, 2003; observer’s own history andNon-commercial this article is no exception. In- Hussner et al., 2010; Winfield et al., 2011; Hermoso et evitably given the author’s research and management ex- al., 2011; liu et al., 2011). The persistent message from perience, the predisposition here will be towards studies of