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Ecology and Biodiversity

Understanding how marine species use the high seas: The Migratory Connectivity in the Ocean (MiCO) system

By Guillermo Ortuño Crespo, Nereus Program Fellow at Duke University

Due to their wide-ranging swimming behaviors, migratory fish, marine mammal, seabird and sea turtle species experience a variety, and an increasing amount, of anthropogenic pressures over the course of their lives. These threats, including climate change, overfishing, and marine pollution, combined with conservation strategies that largely fail to consider spatial connectivity over the life cycle, are resulting in declining populations worldwide.

A review of the impacts of fisheries on open-ocean ecosystems

Due to the expansion of fishing practices, fish catches have become stagnant at best while global fishing efforts continue to grow, ultimately creating major stresses on marine resources. Fisheries impacts on both coastal and deep-sea ecosystems are well understood and documented; however, the biological and ecological impacts of fishing on open-ocean systems are not well studied or documented.

Global spatial distribution of marine species and diversity in the context of climate change

The world is intuitively divided by the existence of recognizable, bounded units of landscape with characteristic climatic regimes and land cover that drives the distribution of existing life on earth. On a global scale, terrestrial ecosystems are grouped into major biomes such as boreal forest, savannah, desert, tundra and grasslands, each with distinct climates, landscapes, species, and vegetation.

Reproductive strategies and rockfish: A life history traits framework for fisheries management

Any trip to an aquarium or seafood market reveals the incredible variety of fishes. These fishes not only differ in how they look, but in traits related to life history. Life history traits include maximum body size, longevity, age at maturity, and fecundity – the number of eggs produced. Fishes that have the same phylogeny, or evolutionary history, share similar traits. Conversely, unrelated fishes occasionally evolve similar traits independently.

From quiet meadows to open ocean: why seagrass meadows are important for fisheries

A meadow under the sea? Not to be confused with seaweeds, seagrasses are land plants that have adapted to living their entire lives submerged in saltwater. They are close relatives of terrestrial grasses, seagrasses are thought to have colonized marine environments several millions of years ago. Different species of seagrass are found in tropic and temperate regions around the world from Southeast Asia to Scandinavia and all around North America. They are known as a “foundation species” because they create important habitat for a wide array of other organisms.

Integrating Sea Around Us fishing catch data into the Madingley ecosystem model

Madingley is a General Ecosystem Model and hopes to indirectly represent all forms of life, terrestrial and marine. Nereus Fellow Phil Underwood works with the Madingley model to validate its use as a policy tool in relation to fisheries, ecosystem health, and food security. He is working to better understand the relationship between oceanic ecosystems and human societies.

Climate change-contaminant interactions in marine food webs

This paper proposes that climate change will alter the effects of pollutants in marine food webs by either directly increasing contaminant exposure (for instance due to receding ice caps), or making organisms more vulnerable to other climate change impacts. It discusses two main classes of contaminants that can affect the health of marine organisms: fat-soluble contaminants known as persistent organic pollutants (POPs), and protein-binding contaminants such as methylmercury (MeHg).

From tiny phytoplankton to massive tuna: how climate change will affect energy flows in ocean ecosystems

Phytoplankton are the foundation of ocean life, providing the energy that supports nearly all marine species. Levels of phytoplankton in an ocean area may seem like a good predictor for the amount of fish that can be caught there, but a new study by Nereus Program researchers finds that this relationship is not so straightforward

The Madingley model and questions of abstraction and scale

Madingley is a global computational model. To a broad approximation, the Madingley model represents all (most) forms of life. It achieves this by using what’s called a functional-type representation. Species are aggregated in to broad categories that describe a select number of their properties, rather than everything about them. For some, this conceptual leap is too much. Why take a step towards representing all life, but miss the explicit inclusion of species? The answer lies in making the best of human knowledge, and balancing computational expense.