The Rule of Capture is one of the first topics law students tackle in any property course. Students learn to examine the rule as it presents itself in a wide variety of cases spanning a time frame from the beginning of American history, like Pierson v. Post, to modern oil and gas cases. The Rule of Capture is explained as: “Qui prior est tempore potior est jure.” (“Who is prior in time is prior in right.”)
 The rule awards capturers with possession of the natural resources they bring under their dominion. Certainly the Rule of Capture is a fundamental concept, but some students may not realize that the history of the rule goes back much farther than early America; like many fundamental legal concepts, the roots of the Rule of Capture can be traced back to the Roman Period. In this post, I will examine the Roman roots of the Rule of Capture and use the Roman ideas accompanying the rule to analyze our modern attempts at marine wildlife conservation.
The Rule of Capture appears at first to be antithetical to modern aims at conservation. Rewarding the capture of wildlife by awarding possession to the capturer seems to do nothing but encourage the reckless use of environmental resources. However, as one traces the history of the rule of capture, it becomes clear that the rule was accompanied by restrictions even as early as the Roman era. 
Romans divided property not belonging to a specific person into three categories: Res Publicae, Res Communes, and Res Nullius. Res Publicae were resources owned by the state, including roads, rivers, as well as public buildings. Res Communes were resources owned in common, including the city’s running water, the sea, and air. Res Nullius were owned by no one; this category included unclaimed land, mineral resources, and wildlife. Objects in the Res Nullius category were subject to the Rule of Capture.
The categories of Res Publicae and Res Communes placed inherent restrictions on the Rule of Capture by reserving certain proprietary interests for the state and the community rather than making those rights alienable to the individual. Of course individuals were free to capture the wild animals in the river, sea, or air, but the communal and state ownership of large natural resources inherently carried restrictions on overuse. Communal ownership (and is counterpart state ownership) implies “Sic utere tuo ut alienum non laedas.” (“One should use one’s own property in such a way as not to injure the property of another.”) 
There were more explicit restrictions on overuse as well. First, the Roman state held de jure power to control the capture of animals. Additionally, the existence of personal land ownership provided some degree of protection to wildlife in that a landowner could exclude others from hunting on his land. While inherent restrictions on overuse through these means of communal ownership, de jure state power to control use, and land ownership might pale in comparison to more aggressive modern attempts at preservation, these early aspects of the law provide the foundation for modern conservation.
In modern American law, wildlife is no longer in the category of Res Nullius but in the category of Res Publicae. This change occurred in the late nineteenth century when states began to declare proprietary interest in the animals. Similarly to Roman law, the state’s proprietary interest (by which I mean the proprietary interest of the government as a whole, not that of a single state necessarily) uses the right of personal landownership to protect wildlife. By setting aside certain lands as wildlife preserves, the state claims ownership over specific plots of land and excludes hunters, just as landownership functioned in the Roman era; except in the case of modern wildlife preserves the land is not in the category of Res in Patrimonium (land owned by an individual) but Res Publicae.
People are familiar with the success of wildlife preserves on land, in which the state strictly limits hunting for the sake of protecting wildlife. However, when the state appropriates the idea of wildlife preserves its waters in the form of Marine Protected Areas (MPAs), on which the state strictly limits fishing, there are certain problems that arise that do not arise for wildlife preserves on land. Firstly, unlike many of the animals that are protected in wildlife preserves on land, a significant amount of animals that are protected in MPAs are a common source of food. Thus, unlike wildlife preserves on land, which have a clearer goal of protecting biological diversity, MPAs are caught between the goals of protecting only fish for the sake of future harvest and protecting all marine wildlife for the sake of biological diversity. Whether an MPA has the goal of protecting a future food source or protecting biodiversity has a profound impact on how states organize MPAs and whether we view marine wildlife protection as an end to itself or as a means of maintaining fisheries.
Additionally, MPAs fail at protecting certain kinds of marine wildlife that are very locomotive. While wildlife in preserves on land can certainly migrate and move outside the preserve (and some migrate quite far), much of the land-dwelling wildlife we seek to protect does not migrate to the extent that marine wildlife does (for example, humpback whales travel over 6500 km, great white sharks travel over 3800 km). Such travel certainly places the animals outside of MPAs (in the U.S., the mean size of an MPA is 703 square km) as well as even outside of state and national borders. Animal migration outside of MPAs works to undermine the protection provided by landownership, and travel outside of state and national borders works to undermine state proprietary interest, both foundational legal bases for wildlife conservation.
While there is of course no perfect solution to these problems, it is important to note that our system of setting aside wildlife preserves and MPAs has been a tremendous step toward conservation. It seems reasonable that if we further expand the foundations of state ownership of wildlife and land ownership, we can further improve our current attempts to preserve marine wildlife. Increasing the protection afforded by land ownership can of course be accomplished by setting aside larger areas for MPAs (some countries are already doing this. The first large MPA was Australia’s Great Barrier Reef Marine Park, founded in 1975; it is 344,000 square km). Increasing the protection afforded by government ownership could be accomplished by combining the ownership of multiple governments through international cooperation, such as has been seen recently between the U.S. and China regarding air pollution.  With efforts that expand our current foundations of marine life preservation, we can augment the progress we have already made in protecting the ocean’s biodiversity.
-Alicia E. Wodarski is a general member at MJEAL. She can be reached at email@example.com
The views and opinions expressed in this blog are those of the authors only and do not reflect the official policy or position of the Michigan Journal of Environmental and Administrative Law or the University of Michigan.
 Jesse Dukeminier et al., Property 3 (Vicki Been et al. eds., 8th ed. 2014).
 Michael C. Blumm & Lucus Ritchie, The Pioneer Spirit and the Public Trust: The American Rule of Capture and State Ownership of Wildlife, 35 Envtl. L. 673, 673 (2005).
 Id. at 677.
 Jesse Dukeminier et al., Property 779 (Vicki Been et al. eds., 8th ed. 2014).
 Id. at 678.
 Id. at 693.
 Id. at 677.
 Robin Kundis Craig, Taking Steps Toward Marine Wilderness Protection? Fishing and Coral Reef Marine Reserves in Florida and Hawaii, 34 McGeorge L. Rev 155, 159 (2003).
 Travis W. Horton et al., Straight as an Arrow: Humpback Whales Swim Constant Course Tracks During Long-Distance Migration, Vol. 5, Issue 7 Biol. Let. 1, 1 (Sept. 12, 2011). rsbl.royalsocietypublishing.org/content/7/5/674 (last visited Nov. 19, 2014),
 Mark Shwartz, Great White Sharks Migrate Thousands of Miles Across the Sea, New Study Finds, Stanford Report (Jan. 9, 2002). news.stanford.edu/news/2002/january9/sharks-19.html
 National Marine Protected Areas Center, marineprotectedareas.noaa.gove/nationalsystem/nationalsystemlist (last visited Nov. 19, 2014)
 Robert J. Toonen, One Size Does Not Fit All: The Emerging Frontier in Large-Scale Marine Conservation, Marine Pollution Bulletin 7, 8 (2013) www.marine-conservation.org/media/filer_public/filer_public/2013/12/16/toonen_et_al_2013_marine_pollution_bulletin.pdf (last visited Nov. 19, 2014)
 Carol E. Lee, Jeremy Page & William Mauldin, U.S., China Reach New Climate, Military Deals, Wall Street Journal (Nov. 12, 2014, 12:42 a.m.), online.wsj.com/articles/u-s-china-ready-deals-to-avert-military-confrontations-1415721451