Physical activity is fundamental for achieving healthy aging. Exercise offers older adults substantial benefits, such as reducing risks of all-cause mortality and chronic disease, preserving functional capacity, improving management of chronic conditions, and reducing health-care costs. Given the prevalence of physical inactivity and sedentary behavior among adults 65 and over, exercise needs to be more thoroughly integrated into care plans and counseling in primary care settings. A practical, three-step approach to exercise counseling is recommended. Older adults should strive to do at least 150 minutes of moderate-intensity aerobic exercise weekly, muscle-strengthening and flexibility activities twice weekly, and for those at risk of falls or with mobility problems, balance activities at least three times per week. Older adults with functional restrictions or chronic conditions should be as physically active as their abilities and conditions allow. Any amount of moderate-to-vigorous physical activity gains some health benefits. Appropriate physical activity counseling, prescription, and referral must be tailored for each patient and must take into account such factors as fitness levels, goals and motivations, access to exercise-related facilities and programs, chronic diseases, prescribed medications, common injuries, and hip and knee arthroplasties.

For any observer of the literature on coral reef fishes it is easy to note that there have been a series of primary topics, each lasting about a decade. Back in the '70s, a lot of attention was given to competition. By the '80s, we had jumped onto the wagon of recruitment and the roles of post-recruitment mortality. And, by the '90s, the focus had shifted to the dispersal of reef fish larvae and their behaviors. This last decade was also very exciting. New discoveries, technologies, and international collaborations yielded important advances in the field of larval dispersal and macro ecological patterns. We also saw the emergence of new disciplines related to social–ecological systems and the impact of human disturbances. Our scientific understanding of reef fishes also rose to an all-time high given that such information is necessary if we are to effectively protect reef systems constantly subjected to anthropogenic stressors. Just consider that during the last decade alone our population grew by about 1 billion people, which undoubtedly has and will continue to put stress on coral reefs, especially since human populations close to most coral reefs could double in size before the end of this century.

Another thing to note about the field of reef fish ecology is that about every 10 years since 1980, Peter F. Sale has delivered general overviews on the state of the knowledge, but none has appeared in the last decade. So the observation that considerable advances have happened in the last decade and that no overview has been written drove me to ask Peter whether he was planning to work on this decade's overview and whether he would let me help continue his legacy. I wrote a nice email, on which I worked for over a week, indicating how necessary this book was and how I was his guy to help and that I will take care of the heavy lifting.

Describing patterns of biodiversity and identifying their underlying causes have been at the core of ecology for decades and have gained momentum since this knowledge is necessary for better diagnoses and preparation for ongoing biodiversity changes. Here, I review the different factors that have been tested to explain large-scale patterns in reef fish richness, particularly the underlying mechanisms of proposed hypotheses. Evidence regarding biodiversity drivers is unclear about the relative roles of variables related to habitat area, isolation, temperature, and the mid-domain effect. In turn, some agreement exists over the relatively minor role of environmental stability and the nullification of Rapoport's rule. Several caveats in available data prevent a better understanding of biodiversity patterns in reef fishes. Yet, evidence is sufficient to suggest that ongoing human-induced environmental changes have the capacity to reshape large-scale biodiversity patterns. The extent to which humanity will become the main driver will depend on how soon such stressors are ameliorated.

Describing and revealing the underlying causes of biodiversity patterns (here referred to as patterns in species richness or the number of species) have been long-standing goals in ecology [620, 2599]. These goals have gained recent interest as such knowledge provides the basis for effective allocation of limited available resources in biodiversity conservation [2123] and scientific grounds for the mitigation of stressors more likely to impact biodiversity (e.g. climate change, habitat loss, etc.) [198, 200, 1191]. Given the human dependency on biodiversity goods and services, understanding the drivers of biodiversity is also critical to assessing how potential changes in biodiversity, arising from ongoing environmental change, could impact societies [492, 1744, 1750].

For coral reef fishes, the general outline of their global pattern of species richness is relatively well documented and accepted. For these taxa, the number of species declines steadily from a peak of high diversity in the “Coral Triangle” (i.e. the area between Indonesia, Philippines, and Papua New Guinea) towards the margins of the Indian and Pacific Oceans (Figure 9.1A) [40, 193, 1733, 1923, 2123].

Coral reefs are in a downward trend despite accelerated efforts for their conservation. This is in much part due to a biased research and conservation focus on the proximal (e.g. overfishing, climate change, pollution, etc.) rather than the ultimate (i.e. an ever-growing and expanding human population) causes of coral reef damage. The expected increase of human populations suggests that proximal stressors will continue, likely exacerbating with each other, and that the current narrow conservation focus will lead to adaptive strategies that will struggle in a perpetual effort to maintain functional ecosystems. A review of MPAs shows, for instance, that the required network of MPAs, in terms of size and connectivity to ensure the viability of coral reef ecosystems, will involve a massive scaling up of protected areas, which will likely be obstructed by limited funding and lack of social and political support and impaired by magnifying threats unlikely to be controlled by MPAs. During the time in which such a network is developed or its expected biological effects become evident, human populations in most tropical countries with coral reefs will have likely doubled. All factors associated with the ongoing decline of coral reefs have human origins, thus I propose that longer-term, more permanent, and perhaps cheaper strategies, to mitigate stressors on coral reefs should include education campaigns to inform people of the social, economic, and environmental consequences of our personal choices regarding child bearing.

Coral reefs are one of the most diverse, socioeconomically important, and threatened ecosystems in the world. Veron [2565] estimated the existence of ~835 species of reef-building corals, which in turn provide home to some 1–9 million other species [2087]. Worldwide, 10% of the human population (~655 million people) live within 100 km of coral reefs [708] and many rely on reefs for the delivery of food, jobs, and revenues at a gross value of over 300 billion annually [380,561,965,1750,1844,2468]. Unfortunately, coral reefs are in a “slippery slope to slime” [1910,1911].

Introduction

One of the most concerning issues to modern ecology and society is the ongoing loss of biodiversity. Ecosystems are now losing species at rates only seen in previous mass extinction events (Hails, 2008; Barnosky et al., 2011) with rates of extinction between 100 and 1000 times higher than pre-human levels (Pimm et al., 1995). This loss, in turn, is impairing the functioning of ecosystems (Worm et al., 2006; Mora et al., 2011a) and their capacity to deliver goods and services to mankind (Díaz et al., 2006). The sharp contrast between the declining “supply” of the Earth’s services and the rising “demand” from a growing human population indicates that such services will increasingly fall short, leading to the exacerbation of hunger, poverty and human suffering (Campbell et al., 2007; Mora & Sale, 2011).

There is relatively good consensus that biodiversity loss is being driven directly or indirectly by human stressors such as overexploitation, habitat loss, invasive species and climate change (Myers, 1995; Sala et al., 2000; Novacek & Cleland, 2001; Gaston et al., 2003; Jackson, 2008; Weidenhamer & Callaway, 2010). The relative role of such stressors, however, has been a focus of controversy as all threats do provide rational mechanisms to explain biodiversity loss and unfortunately most threats co-occur in natural conditions, making it difficult to isolate their individual effects (Myers, 1995; Sala et al., 2000; Novacek & Cleland, 2001; Mora et al., 2007). Since the cost of mitigating specific stressors could be considerable but disproportionate among different sectors of the economy (e.g., industries vs. fishers, fishermen vs. tourism developers, etc.), this uncertainty over the relative effect of anthropogenic stressors is often used as an argument to prevent the implementation of mitigation policies (e.g., Schiermeier, 2004; Worm & Myers, 2004; Grigg & Dollar, 2005).

Introduction

Marine biodiversity is increasingly being lost due to human-related activities. Several marine ecosystems such as estuaries (Lotze et al., 2006), mangroves (Valiela et al., 2001), seagrasses (Waycott et al., 2009), coral reefs (Gardner et al., 2003; Pandolfi et al., 2003; Bruno and Selig, 2007), and coastal and oceanic fish communities (Jackson et al., 2001; Worm et al., 2005) are rapidly losing populations, species, or entire functional groups due to threats such as exploitation, habitat loss, and climate change, among others (Jackson et al., 2001; Hoegh-Guldberg et al., 2007; Mora et al., 2007; Mora, 2008). The rate of these losses and extent of these threats are expected to drive many marine species to collapse and possible extinction before the middle of this century (Worm et al., 2006; Hoegh-Guldberg et al., 2007; Donner, 2009). These losses, in turn, may impair the capability of ecosystems to cope with natural and anthropogenic impacts and harm the services that biodiversity provides to a growing human population that increasingly uses coastal habitats and marine resources (Worm et al., 2006; Donner and Potere, 2007).

The accelerated decay of ecosystems is a modern concern to humankind and has motivated concerted global efforts such as the Convention on Biological Diversity, which was endorsed by more than 190 countries and aimed to reduce the rate of biodiversity loss by 2010 (Balmford et al., 2005). In practical terms, one of the solutions that was proposed and that has received significant support to reverse the loss of biodiversity is the establishment of protected areas (Lubchenco et al., 2003; Balmford et al., 2005; Chape et al., 2005; Lubchenco et al., 2007; Wood et al., 2008). The expected effect of protected areas is that by reducing pressures from harvesting and habitat loss, wild populations will recover if they have been impacted or will maintain natural levels of resilience to cope with natural and other human-related disturbances (Lubchenco et al., 2003; Palumbi, 2003; Micheli et al., 2004; Palumbi, 2004). The fact that such an expected effect has been documented (Halpern and Warner, 2002; Micheli et al., 2004; Worm et al., 2006) and that governments need to fulfill international agreements (Balmford et al., 2005; Wood et al., 2008), has resulted in a proliferation of marine protected areas (MPAs). Today, 4435 MPAs exist worldwide (Wood et al., 2008) covering 0.65% of the world's oceans, although only 0.08% is inside no-take MPAs (Wood et al., 2008). It may be understood, however, that the number and coverage of MPAs are the simplest proxies for biodiversity conservation and that “coverage effectiveness” is what ultimately will determine the real conservation of biodiversity (Chape et al., 2005; Mora et al., 2006). Unfortunately, global assessments on the effectiveness of MPAs are still limited, given the difficulties in collecting data that are patchy and changing rapidly (Mora et al., 2006). Here I analyze a combination of databases to assess the effectiveness of the current global network of protected areas in ensuring the maintenance of populations and the likely constraints that humans pose to the effective management of MPAs.