Shoreline studies at Padre Island point to trash sources--National Park Service--WASO-INFO




					by John Miller

					Trash is a problem at beaches throughout the nation. At Padre Island National Seashore, Texas, shoreline trash has become one of the park's foremost natural resource problems. Approximately 90% of all shoreline trash items found at the seashore are made of plastics, in spite of the fact that an international treaty known as MARPOL prohibits dumping trash at sea, with specific restrictions on dumping plastics. Many marine managers across the nation are seeking ways to clearly identify the sources of shoreline trash so they can try to eliminate the dumping problem at the source. Padre Island might be able to provide some answers. After more than a decade of studying the nature and origin of shoreline trash at the seashore, park resource management staff began analyzing data in 1998 from inventory methods the park pioneered. Padre Island has fine-tuned shoreline trash monitoring techniques and resource management staff have begun to identify the sources of the trash. For 10 years, resource managers at Padre Island National Seashore have tested shoreline trash collection methods in order to determine the survey frequency and distance needed to provide scientifically valid data. Beginning in 1994, and based on findings from previous studies, the park initiated the “Shoreline Trash Point Source Investigation" to identify the amount of trash washing onto the beach from specific sources. This is one of the first long-term, comprehensive, shoreline trash monitoring projects to be conducted in the United States. The labor-intensive project required daily cataloging and removal of 43 different kinds of trash items from 16 miles of shoreline within the park. Upon completion of the 1998 monitoring season, the park had collected 958 days' worth of marine trash data, cumulatively surveyed more than 12,500 miles of shoreline, and recorded and removed nearly 400,000 trash items. Statistical analysis of the data shows that surveys conducted one day per week provide information that can be used to predict the amount and kind of trash that will occur for the entire week. Statistical models derived from the data collected also indicate that surveys should be made every 8–10 miles. This means that at Padre Island, collections can be conducted at miles 1, 8, and 16, instead of all miles 1–16. Additionally, statistical analysis has allowed the park to identify possible sources of the trash. Using data on monthly shrimping efforts provided by the National Marine Fisheries Service, a statistical correlation has been established between Gulf shrimping efforts and the number of specific trash items that wash ashore. A regression model has been developed indicating that increased Gulf shrimping efforts directly correlate with increased numbers of specific types of trash items washing onto the adjacent shoreline. To solve the marine trash problem, point sources must be identified. Actions implemented to reduce the amount of trash being dumped into our oceans are ineffective if the source is unknown. This shoreline trash study demonstrates that monitoring marine trash can aid in identifying probable point sources. This valuable information will be summarized in a technical report in 1999 and can be used for improving the management of marine resources everywhere.
		Entangled in shrimp netting, an endangered Kemp’s ridley sea turtle washed ashore on South Padre Island, south of the park, in 1993, signaling the threat to resources posed by waterborne trash. Photo Credit: Padre Island National Seashore, Roddy W. Wilder john_miller@nps.gov Recently retired Chief, Division of Science, Resource Management, and Interpretation; Padre Island National Seashore, Texas Back to Chapter 2: NPS Science White abalone: Going, going, gone? by Gary E. Davis Riparian monitoring focused on stream recovery in Canyonlands by Charlie Schelz Science-based planning at Tallgrass Prairie National Preserve by John Neal and George Oviatt Recurrent themes of water resources management plans by David L. Vana-Miller Program Center takes on geologic inventories by Bruce Heise and Joe Gregson Bats surveyed at Grand Canyon by Elaine Leslie Survey research provides management information by Jean E. McKendry Home

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Last Updated: 07/22/99
Direct comments on this website to jeff_selleck@nps.gov
This article is from Natural Resource Year in Review--1998, published by the National Park Service, U.S. Department of the Interior, in June 1999 (publication D-1346)