Lucas L. Lutzenkirchen

Aim: To incorporate phylogenetic relationships into Atlantic marine biogeography, investigating how evolutionary history and environmental conditions interact to shape biodiversity patterns at ocean‐basin scales, and to assess how phylogenetic metrics can inform predictions of ecological vulnerability under climate change. Location: Atlantic Ocean. Time Period: Last glacial maximum to 2100. Major Taxa Studied: Reef‐associated ray‐finned fishes. Methods: We integrated the distributions of 1637 species with detailed phylogenetic information to delineate phylogenetically informed bioregions (“phyloregions”). Using phylogenetic diversity, endemism, and evolutionary distinctiveness, we quantified large‐scale evolutionary patterns and applied machine‐learning models with climate projections to forecast future changes in biodiversity structure, including alpha‐ and beta‐diversity metrics and thermal niche breadth. Results: We delineated 19 distinct phyloregions, shaped mainly by past isolation and major oceanographic barriers. Evolutionary distinctiveness was highest in temperate transition zones and remote oceanic islands, while tropical regions emerged as hotspots of phylogenetic diversity and endemism. Future climate scenarios indicate rising phylogenetic diversity and endemism in tropical areas, likely reflecting lineage mixing and range shifts, alongside narrowing thermal niche breadths that signal reduced ecological adaptability. Main Conclusions: The delineation of Atlantic phyloregions reveals how evolutionary legacies, historical climatic dynamics, and major oceanographic barriers have shaped reef fish diversity at ocean‐basin scales. Temperate transition zones and remote oceanic islands harbour highly distinct evolutionary lineages, while tropical regions concentrate phylogenetic diversity and endemism. Coupling this bioregionalization framework with future climate projections further suggests that warming may reorganize assemblage composition and narrow thermal niche breadths across the Atlantic. Together, these findings provide a scalable framework for integrating evolutionary history into conservation prioritization and improving our understanding of biodiversity dynamics under global change.

Ensuring food security in the Anthropocene presents a significant socio-ecological challenge, especially in rapidly changing coastal seascapes that sustain critical fisheries. Herbivorous fishes are essential for food and financial security through fisheries, however, their contributions to regional catches, and the factors influencing them, are not well understood. Analysing reported and reconstructed catch data across 69 Exclusive Economic Zones, we identify shallow-reef area and coastal population density as significant predictors of herbivorous fish catches. However, between-realm (i.e. Indo-Pacific vs. Western Atlantic) differences are marked, with rabbitfishes contributing disproportionately to herbivorous fishery catches. While rabbitfishes have the potential to support productive fisheries due to their relatively faster life-history traits, a 60% decline in catch-per-unit-effort suggests that their production potential, along with parrotfishes and surgeonfishes, may be decreasing globally. Our study highlights contrasting social-ecological outcomes for human populations in the Western Atlantic vs. Indo-Pacific; a difference primarily driven by rabbitfish catches.

Coral reefs are spatially variable ecosystems that form biogenic structures ranging in size from 10 to 1000s of meters. Their changes in response to anthropogenic stress are occurring across increasingly broad scales, yet our ability to detect, understand and respond to these changes at relevant scales is limited. Traditional in-water observation-based coral reef ecology and remote sensing-based methods both offer valuable insights into benthic change, but their relative scalability and use to-date must be understood to inform optimal future research approaches. We conducted a systematic literature review comparing the approaches used to quantify benthic habitat, through traditional in-water ecological studies and remote sensing studies, with respect to: (a) their geographic distribution, (b) reef zone selection, and c) their focal questions. Among the 199 studies reviewed, traditional ecological studies primarily concentrated on community composition (89%), using high-detail direct measurements, especially from the reef slope (80%). By contrast, remote sensing studies provided spatially explicit datasets at coarser spatial and thematic resolutions, with a predominant focus on benthic mapping (72%) across entire reef systems. Only 3% of studies integrated both approaches, combining comprehensive in-situ observations with broadscale remote sensing. As anthropogenic stressors continue to increase in scale, bridging these scientific disciplines offers a promising way to upscale observations to entire reef-scape scales. We identify steps to harness the strengths of both fields and integrate multiple tools at various levels of resolution and scale. Such bridging approaches offer a way forward in understanding and managing coral reef functioning in the Anthropocene.

Aim: The Caribbean and Indo‐Pacific are separate biogeographical realms with distinct biogeographical and evolutionary histories, a 10‐fold difference in biodiversity, and highly disparate sea‐level histories. Since reef morphology often reflects interactions between biological activity and biogeographical history, including sea levels, the widths of shallow coral reef habitats are likely to differ markedly between realms, with ramifications for numerous ecosystem functions. Our goal, therefore, was to assess the impact of global‐scale biogeographical and evolutionary histories on coral reef habitats. Specifically, are Indo‐Pacific reefs wider than their Caribbean counterparts?Location: Global.Time Period: Modern.Major Taxa Studied: Coral reefs.Methods: We used the Allen Coral Atlas, a global reef mapping system (3 m pixel resolution), to examine 3765 transects, 3 km long and 1 km apart, on 60 reefs across the two realms, quantifying shallow reef habitat widths (Inner and Outer Reef Flat, and Reef Crest) using ArcGIS.Results: Shallow reef habitat widths were strikingly similar between the Caribbean and Indo‐Pacific. Estimated modal widths diverged by just 37 m; means by just 122 m. Although shallow reef zones appeared to be wider in the Indo‐Pacific, habitat widths on atolls were almost identical across realms (means varying by less than 8 m).Main Conclusions: Our remote sensing approach provides a global description of the biogeography of coral reefs as biogenic structures. Furthermore, we can assess the relative importance of realm‐wide differences in coral diversity and sea‐level history on reef growth. The striking similarity of reef widths across realms suggests that reef growth (net reef accretion) is largely independent of coral diversity, or sea‐level history, and that other factors may have played a major role in constraining shallow reef widths. These factors may include geomorphology (e.g. antecedent topography and historical accommodation space) and, once at sea level, self‐limiting local hydrodynamics.