Ecosystem Services and Disservices of Bay-Delta Primary Producers: How Plants and Algae Affect Ecosystems and Respond to Management of the Estuary and Its Watershed

The Sacramento–San Joaquin Delta (Delta) is a case-study of the Anthropocene “great accelerations,” with exponentially increasing temperatures and sea level over time, leading to rapid change in other ecosystem components. In nearly all these interconnected changes and across scales, primary producers play a major role, with diverse effects that mitigate or exacerbate rapid change induced by climate or other human-driven perturbations. Through this anthropocentric lens, primary producers can be viewed as performing numerous ecosystem services—which ultimately benefit humans—as well as ecosystem disservices, which have negative effects on human communities. For example, through carbon sequestration, wetlands can perform ecosystem services of mitigating warming at a global scale and combating relative sea-level rise at a local scale, while generating food that supports regional food webs and fisheries. On the other hand, invasive aquatic vegetation (IAV) can trap sediment before it reaches wetlands, exacerbating local subsidence and relative sea-level rise while incurring great costs to recreation, fishing, and agencies tasked with its control. Effectively managing these ecosystem services and disservices requires understanding of how they are connected. For example, wetland restoration often creates opportunities for IAV, which may inhibit sediment deposition on the wetland and outcompete native species. As the Delta science community works toward a more integrative understanding of how different components of the Delta interact as a whole and across scales, the pervasive effects of the ecosystem services and disservices of primary producers serve as foundational knowledge. In this topically themed edition of State of Bay-Delta Science, we review these effects. Individual chapters focus on the historical ecology of the primary productivity of aquatic vegetation, the ecology and control of invasive aquatic vegetation, harmful algal blooms, carbon sequestration and subsidence reversal by wetlands, and remote sensing methods for quantifying the ecosystem services and disservices of Delta primary producers.