Introduction: Honoring the contribution of Charles H. Peterson (1946-2020) to the field of marine ecology

Ecological science addresses a wide variety of research questions, ranging from purely academic to narrowly applied. Major advances in ecology have occurred when fundamental ecological theories were used to formulate questions designed to address pressing practical problems, especially the impacts of human activities in natural ecosystems (e.g., Murdoch, 1994; Tilman et al., 2002; Vitousek et al., 1997). Marine ecologists have played an especially important role in assessing the ecological impacts of anthropogenic disturbances, as well as enhancing our capacity to conserve, manage, and restore marine ecosystems (e.g., Bertness et al., 2014; Jackson et al., 2001; Schmitt & Osenberg, 1996). Charles H. “Pete” Peterson (1946–2020) was a trailblazer and leader in testing, developing, and, most importantly, applying ecological theory to meet environmental challenges (Figure 1). In doing so, he made substantial contributions to ecological science and scholarship. At a time when few academic ecologists wanted to conduct applied studies, Pete performed those studies at a high level of rigor and demonstrated how ecology could be advanced through the application of theory. Pete's rigorous approach to study design, statistical analysis, and interpretation of results showed the flaws in often biased approaches that were being advanced by industry scientists. Pete passed away on October 24, 2020, at his home in Pine Knoll Shores, NC, USA. To help honor Pete's important contributions to ecology we have assembled this Special Feature of Ecosphere in which we present an impressive set of papers that report new results in applied marine ecological science that were inspired by Pete's research, teaching, and mentorship. Inspection of the history of natural science indicates that marine community ecology emerged primarily with the intent to address marine resource management challenges, initially the trophic links between marine benthic invertebrate communities and exploited demersal fish populations in northern Europe (Petersen, 1914). A deeper appreciation of that history reveals how local ecological knowledge helped Pacific Island people manage nearshore marine fisheries sustainably for over a millennium (Johannes, 1981). Yet, as recently as the 1980s, researchers working in applied marine ecology were too often labeled as industry consultants, as nonacademics. Judging from the poor quality of some applied work, the criticism was warranted. Criticism of applied ecology overlapped with a major reexamination, a critique, of ecology captured by Peters (1991). This intradisciplinary assessment followed a transition, led by Professors Joseph Connell (1961) and Robert Paine (1966), in which a qualitative natural-history-based approach, heavily reliant on correlative relationships between community patterns and environmental conditions, evolved to a more theory-driven, mechanistic, and experiment-based form of ecology (e.g., Peterson, 1982). Peters' critique in 1991 initiated the expansion of ecological synthesis science as a means to broaden the generality of research questions and seek answers to the toughest problems we face, including global-scale extinctions, habitat loss, and climate change. Out of these transformative periods emerged a greater appreciation for well-executed applied ecology. Pete Peterson was a leader in this renaissance, especially in the marine environment (e.g., Christensen et al., 1996; Lubchenco et al., 1991). Pete was an exceptionally creative and productive scientist, who made key contributions to many aspects, or subdisciplines, in ecology and marine science. He was highly interdisciplinary in his thinking and general methodological approach. Pete obtained a BA in Biology at Princeton University in 1968 before receiving an MS in Zoology (1970) and a PhD in Biology (1972) working with Professor Connell at the University of California, Santa Barbara. After a brief stint at the University of Maryland (Baltimore County), Pete moved to The University of North Carolina at Chapel Hill, where he taught, advised, and conducted research until he retired in 2019. Over the past half-century, Pete fundamentally transformed our understanding of marine ecosystems while also applying his research to solving environmental problems. He published over 200 peer-reviewed papers, and his research contributed conceptually to ecology, marine biology, environmental sciences, fisheries ecology, restoration ecology, and conservation biology. Trained as a benthic ecologist, Pete used coastal soft-sediment habitats as models to explore how key ecological processes such as competition, recruitment, and predation structure communities. He studied benthic boundary layer systems and fluid dynamics, at small and large spatial scales, to disentangle complex physical–biological processes. Pete examined how habitat created by seagrass beds, salt marshes, oyster reefs, beaches, deep-sea hydrothermal vent organisms, and Antarctic crustaceans influences marine communities and produces ecosystem services. Pete's research advanced basic ecological science, but some of his most profound contributions were in applied marine and fisheries ecology, a field he was influential in establishing. In the latter stages of his career, Pete's work touched on almost every aspect of marine conservation and restoration ecology. He recognized, long before many others, that fishing caused a plethora of ecological disturbances and worked tirelessly to develop sustainable fishing practices and management strategies (Botsford et al., 1997; Jackson et al., 2001; Lotze et al., 2006; Myers et al., 2007; Peterson et al., 1987, 2000, 2003a). He highlighted that oil spilled in coastal marine ecosystems triggers cascades of long-lasting ecological effects (Peterson et al., 2003b). Pete's exceptional capacity to integrate and synthesize ideas across disciplines led to his recognizing that restoring molluscan populations decimated by red tides in coastal North Carolina was critical to local fishers while also providing novel insights into population connectivity and recruitment limitation (Peterson et al., 1996). His work on oyster reef management and restoration ignited a major research emphasis that is now global in scale (Beck et al., 2011; Lenihan & Peterson, 1998). His many contributions to marine conservation were widely recognized and awarded, resulting in a Pew Fellowship and several prizes. Pete spent a large proportion of his career actively shaping policy and engaging in management on a range of environmental issues. He interacted well with politicians, water people, managers, program administrators, and the lay public. Pete served on numerous international and national advisory committees, including ICES (International Council for the Exploration of the Sea), GLOBEC (Global Ocean Ecosystem Dynamics), NSF (National Science Foundation), and NCEAS (National Center for Ecological Analysis and Synthesis). He was equally proud of his work on the North Carolina Environmental Management Commission, just one of the several environmental commissions in the state that Pete served on over the past several decades. North Carolina's coastal habitats and resources are more resilient thanks to Pete's tireless efforts and dedication. Above all, Pete was an educator, mentor, and naturalist. His ability to articulate difficult concepts in the classroom and in the field coupled with his enthusiasm for teaching inspired and enabled many to pursue careers in marine ecology. His passion for nature, whether fishing, birding, or walking with his friends and students, was immense and provided purpose for his scholarly pursuits. He especially liked his daily swims in North Carolinas' Bogue Sound. While rigorous, demanding, and often intense in his mentorship, Pete was always a strong advocate for his students and colleagues. Pete leaves behind a large network of former students, postdocs, and colleagues whose careers he helped shape. Many of those students, postdocs, and colleagues collaborated on this Special Feature that presents 16 papers encompassing a wide spectrum of applied marine ecological research inspired by Pete's examples. These papers are dedicated to the important legacy that Pete built over a long, very productive, and impactful career. Our Special Feature presents papers that report new and exciting results from a suite of important research topics that Pete helped to develop and promote, often with seminal and high-impact publications. Four papers focus on the ecological implications and impacts of anthropogenic disturbance in coastal ecosystems. Swinea and Fodrie (2021) examine the role sustainable fisheries play in the recovery of coastal human societies from catastrophic disturbance, in this case, the massive Deepwater Horizon oil spill in the Gulf of Mexico. Fegley and Michel (2021) advance the way we should quantify the loss and recovery of ecosystem services on beaches degraded by oil spills. Pete played a big role in advancing beach ecology, a fact articulated by Emery et al. (2022), who report on how tides drive cyclical patterns of habitat partitioning by beach invertebrate species. Finally, Donaher et al. (2021) examine how facilitation by bivalves mediates the recovery of seagrass beds from disturbance. Another set of papers examines the role of seagrass as a coastal foundation species, but with a focus on trophic interactions, especially top-down effects on community dynamics. Namba and Nakaoka (2021) examine the influence of environmental conditions on the top-down control of eelgrass populations by herbivores in coastal Japan. Wong and Dowd (2021) explore how the functional traits of component species determine the level of secondary production in eelgrass communities. Alternatively, Geraldi et al. (2022) examine the effects of top-down control on foundation species, in this case the influence of predation on oyster abundance on subtidal oyster reefs. Pete was one of the first researchers to consider the role of landscape processes in driving marine population and community dynamics. To celebrate that research, Van Hoeck et al. (2021) develop a new technique to improve coastal management, specifically the population enhancement of target species, a model system that Pete often used to test both basic ecological theory and as a means to improve management outcomes. Linking land to sea, Gehman et al. (2021) uncover the influence that land use patterns have on estuarine ecosystems by modifying parasite–host interactions. Geissinger et al. (2022) introduce the use of stable isotopes as a technique to examine patterns of habitat use by the little-known, burrowing wrymouth that inhabit nearshore soft-sediment habitats along the US Pacific and Atlantic coasts. A final set of papers helps to advance restoration ecology, a topic of great interest and importance to Pete. Butler et al. (2021) reveal the role sponges play in helping to facilitate coral restoration. Grabowski et al. (2022) and Powers and Grabowski (2023) revisit and extend our understanding of the role that habitat structure, location, and hydrodynamics play in successful oyster restoration efforts. Paxton et al. (2022) provide a framework for better incorporating ecological principles, adaptive management, and experiments in the siting, design, construction, and evaluation of artificial reefs in the coastal ocean. To wrap up the Special Feature, Smith et al. (2022) and Lenihan et al. (2022) report on the ecological impacts of fishing and the use of marine reserves and collaborative fishery research in recovering, restoring, and managing coastal marine fisheries. In summary, the papers in our Special Feature represent a great tribute to the legacy of Charles H. Peterson and are research contributions that would have made him proud.