The use of MTL or MTI in the United States has not received as much attention as in other regions. It is possible that this is because the United States is not party to the Convention on Biological Diversity. As such, the country is not obligated to the conventional laws therein see more and the subsequent recommendations and calls for action. Although the U.S. has not been obliged to explore the use of MTL or MTI in management decisions, the National Marine Fisheries Service (NMFS) has been an active supporter of a shift toward an ecosystem based approach to management. In a 1998 report to Congress developed by a NMFS Ecosystem Principles Advisory

Panel (EPAP), the department outlined the importance of developing an ecosystem based management (EBM) plan as well as guidelines in the development of this strategy. The report highlights that species within an ecosystem are linked trophically and accepts the trend of decreasing MTL, citing “Fishing down food webs… disrupts natural predator-prey relationships and may lead first to increasing catches, but then to stagnating or declining catches” [22]. Among the recommendations issued in the report is the determination of total removals and their relationship to trophic structure. The authors cite Pauly et al., claiming that the

relationship between landings and trophic structure has “potential negative effects on sustainability” [22]. Additionally, the report recommends the development of ecosystem health indices and incorporation of these indices find protocol into regional Fishery Ecosystem Plans (FEP). The Advisory Panel highlighted the use of mean trophic level as such an index, noting that a specific FEP goal could be the maintenance

of a predetermined MTL [22]. More recently, in a 2009 Report to Congress the NMFS reaffirmed their recommendation of an EBM approach to fisheries and the need for “fundamental knowledge of basic ecosystem principles…as outlined by the EPAP” [23]. Ultimately, the use of marine Digestive enzyme trophic indices in policy development and ecosystem management has received sporadic acceptance and adoption. Large intergovernmental and transnational bodies have readily accepted the measure as a suitable indicator of ecosystem health and stability. Several national and regional governing bodies, however, have concluded that the index is only reliable at a larger scale, and not applicable at smaller-scale national levels [17] and [18]. Adoption of MTI as an indicator of sustainable fisheries, however, has been accepted by the CBD, EU, and CLME Project, and many suspect that it will be adopted as a tool for policy development in the European Marine Strategy and Common Fisheries Policy [17]. In 1998, Daniel Pauly and colleagues published a revolutionary study examining change in MTL over time. An examination of global catch data between 1950 and 1994 revealed a startling trend of decreasing MTL over time.