Andrew Johnson

Virginia Institute of Marine Science · Department of Biological Sciences

The marine angiosperm, Zostera marina, utilizes both asexual and sexual reproduction to grow, persist, and recover in dynamic environments. Sexual reproduction could be increasingly important for Z. marina population resilience to extreme weather events resulting from climate change. In the Chesapeake Bay, Virginia, a warming event in 2005 and unpr...

For clonal plants, the role of sexual reproduction in the maintenance of populations can vary widely. Some species are dependent on repeated seedling recruitment. For other species, interactions between adults and seedlings within existing populations can affect seedling survival and limit sexual reproduction in existing populations. Genetic studie...

Herbivores are a diverse group of fauna that shape the distribution and composition of plant communities. In some cases, herbivory may prevent the re-establishment of submerged aquatic vegetation (SAV), such as Vallisneria americana, into systems. The goal of this study was to investigate the role and nature of herbivory on V. americana transplants...

Nearshore‐structured habitats—including underwater grasses, mangroves, coral, and other biogenic reefs, marshes, and complex abiotic substrates—have long been postulated to function as important nurseries for juvenile fishes and invertebrates. Here, we review the evolution of the “nursery habitat hypothesis” and use >11,000 comparisons from 160 pee...

Bioturbating animals have the potential to influence the distribution and survival of seagrass seeds and seedlings within unvegetated substrates. Such disturbances could act as demographic bottlenecks, or restrictions, to seedling recruitment and impede population recovery in degraded systems. This study evaluated the influence of sediment bioturba...

Ocean acidification studies in the past decade have greatly improved our knowledge of how calcifying organisms respond to increased surface ocean CO2 levels. It has become evident that, for many organisms, nutrient availability is an important factor that influences their physiological responses and competitive interactions with other species. Ther...

Ocean acidification studies in the past decade have greatly improved our knowledge of how calcifying organisms respond to increased surface ocean CO2 levels. It has become evident that, for many organisms, nutrient availability is an important factor that influences their physiological responses and competitive interactions with other species. Ther...