The coastal North Pacific: Origins and history of a dominant marine biota

Abstract

Aims Some biogeographical regions act primarily as donors of colonists to other regions, while others act predominantly as recipient areas. How some biotas become dominant while others do not is a largely historical question that has received surprisingly little attention from biogeographers. Here, we seek to answer this question for the cold‐water North Pacific biota, which did not exist forty million years ago but which is now the principal donor biota outside the tropics. Location We focus on the cool‐temperate coastal North Pacific Ocean over the last 36.5 million years. Taxon We consider all multicellular taxa for which adequate fossil, phylogenetic and biogeographical data exist. Methods After placing North Pacific geographical events in the broader context of ocean gateways opening and closing elsewhere in the world, we discuss the history and factors affecting the planktonic and benthic productivity in the North Pacific based on a review and critical evaluation of the literature. A synthesis of primary sources was used to evaluate the origins and fates of North Pacific lineages, with special emphasis on movements to, within and from the North Pacific during the Cenozoic era. Results During the Late Eocene to earliest Miocene, the cooling North Pacific received colonists from adjacent warm‐water regions and the cold Southern Hemisphere, where temperate conditions had existed since at least the Cretaceous. From the Miocene onward, the North Pacific biota began to spread to the Southern Hemisphere and through Bering Strait to the Arctic and North Atlantic Oceans. Within the North Pacific, lineages during the early cooling phases spread predominantly from west to east, but in the Early Middle Miocene this pattern reversed, with later expansions going in both directions. An increase in productivity, powered by the evolution of highly productive seaweeds and by consumers with high metabolic rates, accompanied the transformation of the North Pacific from a recipient to donor biota. Main conclusions The North Pacific replaced the Southern Hemisphere temperate biota as the principal donor biota during the Miocene through a combination of increasing productivity, low magnitudes of extinction and intense competition and predation in an ocean basin with a long coastline.

Phylogeny and Evolution of the Brown Algae

“…Laminariales, Fucales) besides clonal plants (e.g. Arnaud-Haond et al, 2012), and have restructured the dynamics of coastal marine ecosystems around the world (Steinberg et al, 1995;Steneck et al, 2002;Pyenson and Vermeij, 2016;Starko et al, 2019;Vermeij et al, 2019). Brown algae also exhibit striking morphological variation across species, differing substantially in their level of complexity at the levels of cells, tissues and organs (Fritsch, 1935).…”

“…Besides habitat provision, brown algae are a key source of productivity along the coast (Mann, 1973;Pfister et al, 2019) and can significantly increase secondary productivity in nearshore ecosystems through direct herbivory and increased detrital production (Duggins et al, 1989;Krumhansl and Scheibling, 2012). This energy input plays an important role in maintaining food security for many large mammals (Estes et al, 2016;Pyenson and Vermeij, 2016;Vermeij et al, 2019), including humans, and is believed to have facilitated the spread of human populations from Asia to North America prior to the Holocene, the so-called "kelp highway" hypothesis (Erlandson et al, 2015;Braje et al, 2017). As humanity further ventures into the Anthropocene, brown algae are becoming key players in ocean-based strategies for combating climate change given their role in sequestering carbon (Krause-Jensen and Duarte 2016; Krause-Jensen et al, 2018;Hoegh-Guldberg et al, 2019).…”

Comparative biogeography: innovations and the rise to dominance of the North Pacific biota

“…Here I extend this line of enquiry into the world's temperate marine regions. Among modern shallow-water temperate marine biotas, that of the North Pacific is the largest, most diverse and most biogeographically dominant [2]. This biota has exported more lineages to other temperate regions than have the biotas in the Southern Hemisphere and the North Atlantic [2].…”

“…Among modern shallow-water temperate marine biotas, that of the North Pacific is the largest, most diverse and most biogeographically dominant [2]. This biota has exported more lineages to other temperate regions than have the biotas in the Southern Hemisphere and the North Atlantic [2]. Given its dominant status, the North Pacific should have spawned a larger number of functional and ecological innovations than other marine regions outside the tropics.…”

Trophic control of cryptic coralline algal diversity

“…The loss of keystone predators, such as sea otters, can shift the landscape of competitive advantage for coralline algae: Without top-down predation, urchin herbivory is more intense and likely more homogeneous (34), in turn, favoring those coralline species that are tolerant of disturbance, while excluding species that are unable to withstand intense urchin grazing. Because coralline assemblages in the northeastern Pacific have evolved with otters present for millions of years (57), few species may be adapted to these environments of intense herbivory (34). Herbivore-mediated exclusions of algal species have been previously documented (e.g., refs.…”