Edward Emile DeMartini

Biophysical processes associated with large‐scale nearshore oceanographic upwelling can influence coral reef communities by increasing the delivery of nutrient subsidies and food resources to reefs. However, these processes occur alongside anthropogenic activities that may alter ecological patterns across coral reef ecosystems. We examined relationships among nearshore oceanic primary production, human habitation, and the abundance, biomass, body condition and life‐history traits of eight common coral reef fish species across six islands in the Northern Line Islands, central Pacific Ocean. Variation in oceanic primary production and habitation status was associated with differences in abundance, biomass, body condition and life‐history traits (i.e., growth rates, maximum size and longevity) of key coral reef fishes. These relationships varied among species and islands, with some taxa exhibiting more pronounced relationships with productivity and human habitation than others. Among uninhabited islands, several grazer‐detritivore species exhibited life‐history patterns that were consistent with variation in oceanic primary production, whereas these relationships between productivity and life‐history traits were less apparent among inhabited islands. In contrast, piscivore‐invertivore species generally exhibited stronger differences associated with human habitation status. These findings suggest that local human impacts may influence life‐history traits of reef fishes even when strong gradients in oceanic primary production are present. Although the mechanisms underlying these patterns were not evaluated directly, our results highlight the role of biophysical processes in shaping coral reef fish assemblages and suggest that human activities may alter ecological relationships linking environmental conditions and life‐history traits across tropical reef ecosystems.

Cooperative and positive interactions are ubiquitous across all levels of biological organization, and these play critically important roles in the ecology and evolution of natural systems. Among these are long-established interactions between humans and nature to the benefit of both. The development and persistence of these relationships in nature entail processes—mobilization, incentivization, accountability—that can inform approaches for building collaborations across One Health initiatives. Protecting and leveraging these cooperative and positive interactions can facilitate One Health in achieving its goals of optimizing the health of people, animals, and ecosystems. Positive human interventions in the Anthropocene require both human cooperation and learning from lessons from biology to be embraced in how humans interact with nature and one another.

What follows is a look back over a long and productive career and avocation in a field that I love, but one that has also been struck occasionally by personal tragedy, including the loss of my father at an early age, the unexpected death of my beloved wife and life partner in 2010, and a stroke in 2020 that has left me partially disabled. But impactful events can be serendipitous in prompting productive research. The lesson learned by such experiences is that opportunities—and the self-imposed responsibilities—to make positive contributions to the world, and to thereby honor the memories of those lost, continue beyond such events. The lessons I have learned along the way should inspire others at the start of and during their own personal life trajectories, particularly in developing the ability to recognize and appreciate opportunities for mentorship and to inspire emerging scholars and junior researchers to both respond to such opportunities to be mentored and subsequently to be mentors themselves. Everyone, especially students and junior scientists, in particular those who will become resource managers, should realize that they are links in a chain—an important one connecting the past and the future! My goal herein is to use my story to advise students and young scientists, and remind my older colleagues, of the importance of keeping this perspective as they go forward. I have tried to weave this message together with justification for motivation.

Aim: Species ranges provide a valuable foundation for resolving biogeographical regions, evolutionary processes and extinction risks. To inform conservation priorities, here we develop the first bioregionalization based on reef fish abundance of the Hawaiian Archipelago, which spans nearly 10° of latitude across 2,400 km, including 8 high volcanic islands in the populated main Hawaiian Islands (MHI), and 10 low islands (atolls, shoals and islets) in the remote northwestern Hawaiian Islands (NWHI).Location: The Hawaiian Archipelago.Taxon: Fishes (276 taxa).Methods: We compiled 5,316 visual fish surveys at depths of 1–30 m from throughout the Hawaiian Archipelago. Geographical range (km²) for each species was measured as extent of occurrence (EOO) and area of occurrence (AOO). PERMANOVA and PCO were used to investigate drivers of fish assemblage structure. Distance‐based multivariate analyses were used to evaluate the relationship between fish assemblage structure and predictor variables including latitude, reef area, temperature, chlorophyll‐a, wave energy and human population density.Results: Distinct fish assemblages exist in the MHI and NWHI, with two additional faunal breaks driven primarily by endemic species abundance. Latitude explained 37% of the variability in fish assemblages, with reef area accounting for an additional 9%. EOO showed a significant correlation with latitude. Endemics comprised 52%–55% of the numerical abundance at the northern end of the archipelago but only 17% on Hawai‘i Island in the extreme south. Maximum size and activity regime (day vs. night) explained the most variation in the abundance of endemics.Main conclusions: The Hawaiian fish assemblages are strongly influenced by endemic species, affirming the archipelago as a biodiversity hotspot of high conservation value. The higher abundance of endemics in the NWHI may represent preadaptation to oceanic (oligotrophic) conditions. Resolution of distinct bioregions across the archipelago provides a better understanding of reef fish macroecology, with implications for management at the archipelago scale.

Surprisingly little published information exists on the pros and cons of managing extracted resources that are pooled as compound taxa such as species complexes. Current fisheries management includes many species complexes; in Hawaii, this includes two taxa of species pooled at subfamily and higher levels. These include seven species of parrotfishes (Scarinae, Labridae) and a seven‐species ‘bottomfish’ complex (the ‘Deep‐7’: comprising six species of snappers [Etelinae, Lutjanidae] and a single species of grouper [Epinephelidae]). Recent research on key vital rates (growth, reproduction) for major species in both taxa indicates that these complexes consist of species with disparate life histories. Species in the parrotfish taxon exhibit fast to very fast growth and short to moderate longevities, whilst Deep‐7 bottomfishes exhibit moderate to very slow growth and long to very long lifespans. These data clearly indicate that, although pooling species is a tempting default option in data‐poor situations, it is at best a necessary evil to be avoided when sufficient data on the demographics of component species become available. Pooling species is especially problematic when the ecosystem effects of extracting functionally dominant species should be an important management consideration in addition to that of species demographics. Assessments that recognize and quantify the ecosystem importance of habitat engineers and other ecological dominants could substantively improve management of species complexes. Ultimately, complexes of resource species need to be evaluated and managed based on many, sometimes conflicting and sometimes reinforcing, but always careful considerations such as those contrasted herein between the parrotfishes and bottomfishes of Hawaii.

A microscopic morphological feature (eosinophilic granulocytes, eG) was recently detected in the gonads of two species of economically important and broadly distributed, tropical Indo-Pacific eteline snappers, primarily in the ovaries of mature but reproductively inactive female Ruby Snapper Etelis carbunculus. Eosinophilic granulocytes have been known for more than a century to occur in diverse tissues (e.g., liver, kidney, gill, gonad) of a variety of freshwater and marine teleosts and have usually been recognized as bio-markers of immune response to environmental toxins or pathogens. Until now, they have been mostly overlooked as indicators of natural atresia in gonads and evidence of prior reproductive function in healthy fishes. The eG feature is herein suggested as a bio-marker of sexual maturity that might be useful when combined with an existing suite of largely qualitative markers of maturity in mature females that lack direct signs of maturity such as atretic yolked oocytes and post-ovulatory follicles. This marker may reduce the present uncertainty in distinguishing mature but inactively reproducing females from immature females in studies of fish and fisheries biology, specifically when estimating body size at sexual maturity.

Bluespine unicornfish (Naso unicornis) from Hawaii were aged to >50 years using cross-sectioned sagittal otoliths. Fish length was a poor indicator of age because of rapid and variable early growth, exemplified by fish aged to be 4 years near maximum length. Growth was deterministic with adult ages decoupled from body length. Otolith mass and thickness were evaluated as proxies for age and both were encouraging; thickness explained more variance but mass was easier to measure. An age estimation protocol was validated through ontogeny using bomb radiocarbon (¹⁴C) dating. Use of the postbomb ¹⁴C decline period from a regional reference chronology enabled age validation of young fish — a novel approach for the Pacific Ocean. A probabilistic procedure for assigning bomb ¹⁴C dates (CALIBomb) was used for the first time to determine fish birth years. The age-reading protocol was generally validated, and it was possible to describe length-at-age despite difficulties in counting otolith annuli beyond 30–40 years. Growth curves differed between the sexes, and a four-parameter generalized von Bertalanffy growth function provided the best fit.