U.S. State Maps
The Maps and Data section of this toolkit provides state-by-state directories of digital data relating to Marine Conservation Agreements (primarily ownership and leasing) within ocean and coastal waters of the United States. (Select a U.S. State in the navigation menu on the left or the interactive map below.)
Data for all ocean coast states was initially assessed from June 2007 to October 2007, although not all states were assessed at the same level. In 2010 The Nature Conservancy conducted a Nationwide Assessment of State-level Marine Cadastre Data through phone interviews and written inventories completed with the help of state marine data managers.
A rigorous process to develop ownership, management and use data is presented in detail in the guidelines, Marine Land Ownership & Leasing Spatial Database Template (pdf, 223k). The template was designed to facilitate spatial data projects and to enable comparisons of progress among different state and country spatial databases. The template was used in 2006 to assess and develop spatial data for MCAs in Oregon (pdf, 464k) and Massachusetts (pdf, 2,117k).
When planning and implementing conservation activities or other human activities within the ocean and coastal environment, among the essential questions are: 1) who is able to use the areas; 2) who possesses rights to the areas; 3) what restrictions are placed on the areas; and 4) who has responsibilities over the areas. At the state and local government level the responsibility for allocating rights and managing records is often dispersed across a number of different agencies and organizations. As such, it is difficult to find and acquire the data needed to depict usage, rights, restrictions and responsibilities that are needed to conserve natural resources or manage human uses in the ocean and coastal environment.
A marine cadastre would directly address this issue. A cadastre is an official register of properties or parcels and the rights and interests related to them. A marine cadastre should include a description of parcel boundaries, the associated rights, restrictions, management responsibilities and, ideally, ecological characterizations of the parcels. The utility of a marine cadastre increases with the degree of completeness of its geography, the ability to account for the different jurisdictional responsibilities that overlap parcels and the level to which the natural and geophysical characteristics associated with parcels can be described.
This section of the toolkit is an effort to make up for the widespread absence of marine cadastres in state waters by identifying and indexing many of the different data sources that would be useful to marine conservation efforts and should be included in marine cadastres. During the process of collecting this information an assessment was made of the status of the marine cadastre and coastal water information infrastructure in each state in order to provide details about marine cadastres, current conditions for state coastal waters, and a strategy for moving towards implementation of a multi-purpose marine cadastre for state coastal waters.
If you have information regarding the availability of digital data that you would like to be considered for posting or you discover errors or omissions in the information provided in the toolkit, please Contact Us.
Using Maps and Associated Data
Digital maps and other data have limited accuracy and may contain errors. In most cases, the maps and spatial data provided in the toolkit directories are not legal determinations of property boundaries or other matters. Appropriately, the data providers generally publish disclaimers that should be acknowledged before the information is used.
Except in the cases of Massachusetts and Oregon, where The Nature Conservancy completed detailed spatial data assessments, we have not usually examined the data files nor discussed with data managers the availability and content of data. Consequently, although we have attempted to be conscientious and thorough, we may have missed some important publicly available data sets, or mischaracterized data that is listed.
U.S. State Information
For each U.S. State you will find listings of maps and data available over the Internet, divided into the following sections:
- GIS Portals
- Submerged Lands Boundaries
- Leases and Other Use Authorizations
- Local Parcel Information
As state pages are updated with the results of the marine cadastral data assessment, you will encounter the following additional sections:
- Reference and Supporting Data
- Marine Jurisdictional Boundaries
- Marine Managed Areas
Most states have one or more GIS portals—a state agency, state agencies, or a users’ network that lists sources of GIS data. Many of these have a catalog of available data layers, a searchable metadata database, downloadable data, or an online interactive mapping application. While our directories focus on ownership and leasing data, many states have other physical, biological, jurisdictional, and cultural data relevant to ocean and coastal resources that will be of interest to conservation practitioners. If you do not find the data set you need in our state directories, these GIS portals may help you find it.
Maps and data illustrating the landward, seaward, and lateral boundaries of state ocean and coastal lands, when available, provide basic orientation to users. For simplicity and uniformity in presenting data, we have called these submerged lands boundaries, while being aware that different states call these areas tidelands, water bottoms, and other terms, or use submerged lands in a more restrictive sense.
When using any delineation of submerged lands boundaries, take care to understand how the boundaries have been defined and mapped for that data set. In addition to submerged lands lying within ocean and coastal waters, delineations may include freshwater submerged lands; or may represent only state-owned submerged lands, waters of the Coastal Zone, or the area in which the state protects public trust rights, and each of these may have different boundary definitions.
Submerged Lands Parcels
A few states have mapped parcels or tracts of state and private ownership in ocean and coastal waters. Where this has been done, these maps are of great usefulness. In some cases, these maps may be associated with leasing data as well as ownership data. When using this data, be careful to understand what is being represented. For instance, does the data depict the extent of state-owned tracts, or both state-owned and privately-owned parcels?
General Property and Parcel Data
Records of submerged lands ownership should be reflected in official property records. Legally, ownership of land is identified through deed records, which may or may not reference underlying land surveys or plats of subdivision. Property boundaries are most commonly determined by a professional surveyor working from deed records, plats and surveys, and monuments on the ground. In practice, a common method for planning purposes is to use property tax assessment data, which generally includes current ownership, a tax parcel number, and maps showing the taxed parcels. In most states both deed recording and tax assessing are done by local governments—either county governments or, in New England, municipal governments. But a few states either handle one of these functions on the state level or have gathered the data from local governments to provide statewide data. In most cases, look to Local Parcel Information for locally available property and parcel data.
Public and Conservation Lands
Many states map state-owned lands, state-managed lands, government-owned lands, protected open space, or some subset of these, such as wildlife refuges. Maps of public lands and conservation lands may (or may not) include public or protected lands in ocean and coastal waters. Even if they do not, this information can be helpful in identifying public and conservation lands along the coast.
Aquaculture and Shellfish
One of the most common use authorizations for ocean and coastal land is aquaculture or shellfish harvest. As shellfish restoration is a common conservation activity in coastal waters, maps and data on shellfish leases are valuable, when available.
Other Use Authorizations
Other use authorizations include oil, gas, and other mineral leases; authorizations for marinas, docks, revetments, cables, or other structures; dredging and dredge disposal licenses or permits; and more. They may also include leases to conservation organizations.
Many local jurisdictions record deeds, assess property for tax purposes, and maintain parcel maps. Some of this local information is available digitally and spatially, which may be helpful when determining ownership in ocean and coastal areas. Because there are many counties in the United States, our data descriptions are very brief, and you will need to examine the data to determine its usefulness. If you use this type of data frequently, you may want to investigate commercial services that provide online access to much of this data regionally or nationally. [If local parcel information is not yet posted for your state, we hope to post it in a future iteration of the toolkit.]
Deed records may provide summary index data, or may include viewable images of the recorded documents. Some county web sites charge a fee for access, for viewing images, or for advanced search options. For an orientation to land records in your state, you can begin by consulting the Land Records Research Directory web site.
Assessment data is increasingly common, but is often geared more for taxpayers than land research. Check whether it includes the parcel number, which is useful for cross-referencing to parcel maps.
Parcel maps may be scanned images of paper maps or interactive GIS maps, and may or may not be associated with detailed assessment data. Occasionally they are available for download in a GIS format. Be aware that parcel maps do not generally have high precision or accuracy. For tax assessing purposes, general location, configuration, and area are more important than precise, accurate boundaries. While some online parcel maps and property search sites will allow you to retrieve data on a group of parcels, others will only report data one record or parcel at a time.