Browsing by Author "Lozier, MS"

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Open Access
Local stratification control of marine productivity in the subtropical North Pacific
(Journal of Geophysical Research: Oceans, 2010-01-01) Dave, AC; Lozier, MS
Strengthened stratification of the upper ocean due to global warming is generally expected to inhibit marine primary productivity in the subtropics, based on the supposition that increased water column stability will decrease vertical mixing and consequently the entrainment of deep nutrients into the euphotic zone. A recent analysis of observational data from the subtropical North Atlantic, however, demonstrates that productivity in this region is not correlated with stratification on interannual time scales over the modern observational record, but is instead impacted by other dynamics that affect vertical mixing and nutrient supply. Herein, we examine data from the Hawaiian Ocean Time series program's Station ALOHA (A Long-Term Oligotrophic Habitat Assessment) in the subtropical North Pacific. We find that stratification and productivity are not strongly correlated at this location over the observational record. In contrast to the North Atlantic, the weakness of correlation observed at ALOHA may reflect the strongly stratified ecosystem of the eastern subtropical North Pacific and a lack of sufficiently strong interannual forcing in this region. Although basin-wide climate processes (namely El Nio-Southern Oscillation and Pacific Decadel Oscillation) have previously been suggested to impact local stratification and vertical nutrient supply at ALOHA, we find no evidence of a strong or consistent linkage. Comparing local ecosystem variability to the recently identified North Pacific Gyre Oscillation, however, we observe a correlation with local subsurface productivity and salinity. The correlations have similar structure in both space (i.e., depth) and time and are possibly linked to dynamics associated with the formation and advection of water masses in the central gyre. © 2010 by the American Geophysical Union.
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Physical controls on the seasonal migration of the North Pacific transition zone chlorophyll front
(Journal of Geophysical Research: Oceans, 2010-01-01) Ayers, JM; Lozier, MS
The large seasonal migration of the transition zone chlorophyll front (TZCF) is of interest because a number of marine fauna, both commercial and endangered, appear to track it. Herein we examine the physical dynamics driving this seasonal migration of the TZCF. Vertical processes, traditionally viewed as controlling the dynamical supply of nutrients to surface waters, prove insufficient to explain seasonal variations in nutrient supply to the transition zone. Instead, we find that the horizontal Ekman transport of nutrients from higher latitudes drives the TZCF's southward migration. The estimated horizontal transport of nitrate supports up to 40% of new primary productivity in the region annually and nearly all of new primary productivity in the winter. The significance of horizontal advection to the North Pacific transition zone supports revising the paradigm that nutrients are supplied to surface waters from below. © 2010 by the American Geophysical Union.
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Steering the global partnership for oceans
(Marine Resource Economics, 2014-01-01) Abbott, J; Anderson, JL; Campling, L; Hannesson, R; Havice, E; Lozier, MS; Smith, MD; Wilberg, MJ
The Global Partnership for Oceans (GPO) is an alliance of governments, private firms, international organizations, and civil society groups that aims to promote ocean health while contributing to human wellbeing. A Blue Ribbon Panel (BRP) was commissioned to develop guiding principles for GPO investments. Here we offer commentary on the BRP report from scholars in multiple disciplines that study the oceans: environmental economics, environmental politics, fisheries science, physical oceanography, and political economy. The BRP is a prominent, unique group of individuals representing diverse interests of GPO partners. We applaud the call for knowledge creation, but identify diverse issues that the BRP omitted: the need for effective governance to address data-poor stocks so that gaps do not dictate solutions; the deployment of projects that facilitate learning about governance effectiveness through program evaluation; and the importance of large-scale coordination of data collection in furthering the BRP's call for capacity building. Commenters' opinions are mixed on the likely impact of the report's recommendations on ocean health, governance, and economic development, but they highlight several key features of the report. A centerpiece of the report that distinguishes it from most previous high-level reports on the oceans is the prominence given to human well-being. The report emphasizes the commons problem as a critical institutional failure that must be addressed and focuses heavily on market-based mechanisms to improve governance. The report successfully acknowledges tradeoffs-across different stakeholders as well as across human well-being and ocean health-but there is little specific guidance on how to make these tradeoffs. Historical tensions among GPO partners run deep, and resolving them will require more than high-level principles. For instance, it is unclear how to resolve the potential conflict between proprietary data and the report's stated desire for transparency and open access to information. Some differences may ultimately be irreconcilable. The report appropriately advocates flexibility for the GPO to adapt solutions to particulars of a problem, avoiding the trap of one size fits all. However, flexibility is also a weakness because the BRP does not provide guidance on how best to approach problems that span multiple scales. Some scales may be beyond the scope of the GPO; for example, the GPO cannot meaningfully contribute to global climate change mitigation. Nevertheless, the GPO could play an important role in climate adaptation by facilitating the development of governance regimes that are resilient to climate-induced species migrations.