Developing Salt-Marsh Restoration Strategies to Optimize Habitat Use by the Blue Crab, Callinectes sapidus (2009)

Metadata:

• Identification_Information
• Data_Quality_Information
• Entity_and_Attribute_Information
• Distribution_Information
• Metadata_Reference_Information

Identification_Information:

Citation:

Citation_Information:

Originator:

Dauphin Island Sea Lab: Aronson Lab

Publication_Date:

Unpublished material

Title:

Developing Salt-Marsh Restoration Strategies to Optimize Habitat Use by the Blue Crab, Callinectes sapidus (2009)

Description:

Abstract:

This study focused on the predator-prey relationship of the blue crab, Callinectes sapidus, to the marsh periwinkle, Littoraria irrorata, and olive nerite, Neritina reclivata, to determine the extent of resource utilization by blue crabs in created marsh of different ages and unaltered reference sites in coastal Alabama. The following metrics were compared among sites: (1) predation potential imposed on Littoraria and Neritina by Callinectes, as measured by tethering experiments; (2) the frequency of sublethal injuries in shells of Littoraria and Neritina; (3) shell morphology of Littoraria and Neritina; (4) Callinectes abundance; and (5) the physical structure provided by the smooth cordgrass, Spartina alterniflora, and the black needlerush, Juncus roemerianus. All predation metrics were significantly and positively correlated with one another and crab activity was regulated by the filtering effect of Spartina and Juncus. By integrating dynamical measures of predator–prey interactions with comparisons of the availability of potential prey species, this study provides a mechanistic view of the development of ecological function and the potential for energy export in restored salt-marsh habitats.

Purpose:

This study enabled us to cover a broad range of conditions under which marshes provide critical habitat and prey resources for blue crabs, Callinectes sapidus, in the Mobile Bay National Estuary Program (MBNEP) study area.

Time_Period_of_Content:

Time_Period_Information:

Range_of_Dates/Times:

Beginning_Date:

200901

Ending_Date:

200910

Currentness_Reference:

ground condition

Status:

Progress:

Complete

Maintenance_and_Update_Frequency:

As needed

Spatial_Domain:

Bounding_Coordinates:

West_Bounding_Coordinate:

-88.4722

East_Bounding_Coordinate:

-88.1776

North_Bounding_Coordinate:

31.1800

South_Bounding_Coordinate:

30.1988

Keywords:

Theme:

Theme_Keyword_Thesaurus:

None

Theme_Keyword:

salt marsh

Theme_Keyword:

restoration

Theme_Keyword:

habitat use

Theme_Keyword:

cascading ecosystem effects

Theme_Keyword:

trophic linkages

Theme_Keyword:

predator-prey relationship

Theme_Keyword:

abundance

Theme_Keyword:

diversity

Theme_Keyword:

population density

Theme_Keyword:

predation

Theme_Keyword:

energy flux

Theme_Keyword:

quadrat surveys

Theme_Keyword:

tethering

Theme_Keyword:

sublethal injuries

Theme_Keyword:

morphometric analysis

Theme_Keyword:

shell repairs

Theme_Keyword:

trophodynamics

Theme_Keyword:

vegetation density

Theme_Keyword:

plant density

Theme_Keyword:

shell morphology

Theme_Keyword:

sublethal injury

Theme_Keyword:

keystone predator

Theme_Keyword:

blue crab

Theme_Keyword:

Callinectes sapidus

Theme_Keyword:

marsh periwinkle

Theme_Keyword:

Littoraria irrorata

Theme_Keyword:

olive nerite

Theme_Keyword:

Neritina reclivata

Theme_Keyword:

black needlerush

Theme_Keyword:

Juncus roemerianus

Theme_Keyword:

smooth cordgrass

Theme_Keyword:

Spartina alterniflora

Theme:

Theme_Keyword_Thesaurus:

ISO 19115 Topic Categories

Theme_Keyword:

biota

Theme_Keyword:

environment

Theme_Keyword:

inlandWaters

Theme_Keyword:

oceans

Place:

Place_Keyword_Thesaurus:

None

Place_Keyword:

Gulf of Mexico

Place_Keyword:

Alabama

Place_Keyword:

Gulf Coast

Place_Keyword:

Dauphin Island

Place_Keyword:

Mon Louis Island

Place_Keyword:

Fowl River

Place_Keyword:

Weeks Bay

Place_Keyword:

Fish River

Place_Keyword:

Little Dauphin Island

Place_Keyword:

Airport Marsh

Place_Keyword:

Estuarium Marsh

Place_Keyword:

Dauphin Island Sea Lab

Place_Keyword:

DISL

Access_Constraints:

Permission to access these data must be given by Dr. Richard Aronson of Florida Institute of Technology.

Use_Constraints:

Acknowledgment of the Marine Paleoecology Lab, Dauphin Island Sea Lab, and Mobile Bay National Estuary Program is required in products developed from these data, and such acknowledgment as is standard for citation and legal practices for data source is expected by users of these data. Users should be aware that comparison with other data sets for the same area from other time periods may be inaccurate due to inconsistencies resulting from changes in mapping conventions, data collection, and computer processes over time. The distributor shall not be liable for improper or incorrect use of these data, based on the description of appropriate/inappropriate uses described in the metadata document. These data are not legal documents and are not to be used as such.

Point_of_Contact:

Contact_Information:

Contact_Person_Primary:

Contact_Person:

Richard Aronson

Contact_Organization:

Florida Institute of Technology

Contact_Position:

Principal Investigator

Contact_Address:

Address_Type:

mailing and physical

Address:

Department of Biological Sciences

Address:

Florida Institute of Technology

Address:

150 West University Boulevard

City:

Melbourne

State_or_Province:

FL

Postal_Code:

32901

Country:

USA

Contact_Voice_Telephone:

(321) 674-8034

Contact_Electronic_Mail_Address:

raronson@fit.edu

Contact_Instructions:

Please email Dr. Aronson for further information.

Data_Set_Credit:

Ryan Moody

Native_Data_Set_Environment:

Spreadsheets were created using Microsoft Excel.

Data_Quality_Information:

Logical_Consistency_Report:

not applicable

Completeness_Report:

Data was gathered and processed in the lab from 200901-200910 with no major lapses in collection.

Lineage:

Process_Step:

Process_Description:

Study Sites In addition to four existing study sites, we established three sites within Weeks Bay. These new sites were located along a south-to-north gradient to assess the effects on predator–prey relationships of the replacement of Littoraria by Neritina, the increasing dominance of Juncus, and the covarying demographic shift of Callinectes sub-populations from adult to juvenile dominance. Our existing sites included the created, 2-ha Estuarium Marsh adjacent to the Dauphin Island Sea Lab (DISL) and an altered 2-ha site, Airport Marsh, located 8 km west of the Estuarium Marsh on Dauphin Island. We established both of these study sites in November 2005. In December 2006 we added two 2-ha areas of a marsh restored three years ago at the mouth of Fowl River, one of which was retained for monitoring in this study. Lastly, we established a 2-ha site in an unaltered marsh on Little Dauphin Island in July 2007. These sites are physiographically similar in that they surround small, blind-ended tidal ponds and are composed primarily of fringing, tall-form Spartina. The three new, unaltered sites were established on the western shore of Weeks Bay: (1) a southerly site (hereafter referred to as WB-2) adjacent to the mouth of Weeks Bay, composed of both Spartina and Juncus and inhabited by Littoraria (Neritina absent); (2) a mid-bay site (WB-4), containing a mixture of Spartina and Juncus, and both Littoraria and Neritina; and (3) a northerly site (WB-7), composed of monospecific stands of Juncus inhabited by Neritina but not Littoraria. The sites were chosen for their physical similarity to our existing sites in western Mobile Bay. Trophic Relationship Between Blue Crabs and their Gastropod Prey (1)Tethering experiments We conducted five tethering trials, replicated approximately biweekly across randomly selected tidal cycles, at each site from March to May 2009. Tethering trials were not performed at LDI. We tethered ten live Littoraria and Neritina simultaneously at each site to determine whether patterns of tethering losses in both species revealed similar among-site differences in predation, as measured by sublethal repair and shell morphology. Snails were affixed to short lengths of fishing line and tethered individually to randomly selected shoots of vegetation at each marsh. All snails were tethered within 3 m of the shoreline. At the conclusion of each tethering trial, we assessed and compared rates of predation, both lethal (complete shell destruction and snail death) and sublethal (survival with shell damage). (2)Sublethal injuries Sublethal injuries result from unsuccessful predation attempts by shell-crushing predators and subsequent shell repair by the prey. Assessments of repaired shell damage provide a time-integrated record of predator activity in slow-moving, non-migratory species, and were assessed at each site for Littoraria and Neritina. Shell erosion is common on the spires of both species, and assessments of repaired sublethal injuries were restricted to scars on the surface of the body whorl. Sublethal damage was assessed under a dissecting microscope or magnifying lens. We collected 30–50 live Littoraria from each of two size classes (medium: 13.00–17.99 mm shell length [SL]; and large: 18.00-24.50 mm SL) at each site in January (Winter), April (Spring), June (Early summer) and September (Late Summer) 2009. Littoraria were not present at WB-7 for the duration of the study period, and large snails were not present at Estuarium Marsh during any of the four collection periods. All snails were collected within 3 m of the shoreline. An identical collection regime was followed for Neritina at the four sites where the species occurred naturally: WB-2, WB-4, WB-7 and Fowl River. Live Neritina of 10–17-mm SL were collected for assessments of sublethal repair. (3) Architectural defenses in Littoraria and Neritina shells Littoraria alters its shell morphology in response to water-borne cues produced by Callinectes (Moody and Aronson, in prep.). The resulting changes, which primarily involve shell thickening, are correlated with frequencies of sublethal repair and the local abundances of crabs. Neritids alter their shell morphology in response to their physical and chemical environment, but it is not known if they are capable of responding morphologically to predators. Architectural defenses were assessed seasonally for both species using a species-specific suite of morphological measurements. Littoraria exhibit variable shell morphologies throughout ontogeny and were, therefore, separated into two size classes to control for size effects: medium (15–18 mm) and large (18–24 mm). No such ontogenetic differences were observed for Neritina. (4) Callinectes abundance and size We assessed crab abundance by deploying baited crab traps covered in plastic mesh (to retain the smaller individuals) on the tidal cycle following each tethering trial. Previous demographic studies of Callinectes in Weeks Bay showed that juvenile crabs typically concentrate in the northern areas of Weeks Bay, whereas adults are taken in large numbers near its southern mouth. Crab abundance and size were used to determine whether size-specific patterns of predation by Callinectes were reflected in among-site differences in shell repair in Littoraria and Neritina, and shell morphology in Littoraria. Crab abundance was not assessed at LDI. Physical/Biological Structure of Spartina and Juncus We assessed densities of Spartina and Juncus at each site, together with Littoraria and Neritina densities, using standard quadrat survey methods. These density estimates were used in tandem with Callinectes densities to determine how the structure provided by emergent macrophytes influences predation on both species of snails. Floral and faunal densities were measured using 5 randomly thrown 0.5-m2 quadrats at each site. All quadrats were thrown within 3 m of the shoreline. Density assessments were conducted seasonally in tandem with snail collections for sublethal repair.

Process_Date:

Unknown

Process_Contact:

Contact_Information:

Contact_Person_Primary:

Contact_Person:

Richard Aronson

Contact_Organization:

Florida Institute of Technology

Contact_Position:

Principal Investigator

Contact_Address:

Address_Type:

mailing and physical

Address:

Biological Sciences Department

Address:

College of Science

Address:

Florida Institute of Technology

City:

Melbourne

State_or_Province:

FL

Postal_Code:

32901

Country:

USA

Contact_Voice_Telephone:

(321) 674-8034

Contact_Electronic_Mail_Address:

raronson@fit.edu

Contact_Instructions:

Please email Rich Aronson for further information.

Entity_and_Attribute_Information:

Overview_Description:

Entity_and_Attribute_Overview:

Excel tables cataloging data in the following categories: Littoraria morphometrics, Littoraria repairs, Nerite morphometrics, Nerite repairs, population densities, tethering data, and crab trap data.

Entity_and_Attribute_Detail_Citation:

Littoraria morphometric data includes the following attributes: site, collection (date), shell height, spire height, body whorl width, aperture width, aperture height, LipU, LipL, LipC.

Entity_and_Attribute_Detail_Citation:

Littoraria repair data includes the following attributes: site, collection (date), snail identification number, shell length, body whorl scars, spire scars.

Entity_and_Attribute_Detail_Citation:

Nerite morphometric data contains the following attributes: site, collection (date), shell height, spire height, body whorl width, aperture height, LipU, LipL, LipC.

Entity_and_Attribute_Detail_Citation:

Nerite repair data contains the following attributes: site, collection (date), snail identification number, shell length, spire height, body whorl scars.

Entity_and_Attribute_Detail_Citation:

Population density data contains the following attributes: site, date, quadrat number, and number of the following individuals found within the quadrat: Spartina, Scirpus, Geukensia, Littoraria, hermit, burrows, Neretina, Melampus, Juncus.

Entity_and_Attribute_Detail_Citation:

Tethering data includes the following attributes: site, tether number, species, outcome, proportion (predation events/total # tethered individuals).

Entity_and_Attribute_Detail_Citation:

Crab trap data includes the following attributes: site, set time, set salinity, collect time, collect salinity, male spine-spine length, male notch-notch length, female spine-spine length, female notch-notch length.

Distribution_Information:

Distributor:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization:

Dauphin Island Sea Lab

Contact_Position:

Data Management Specialist

Contact_Address:

Address_Type:

mailing and physical

Address:

101 Bienville Blvd.

City:

Dauphin Island

State_or_Province:

Al

Postal_Code:

36528

Country:

USA

Contact_Voice_Telephone:

251-861-2141

Contact_Electronic_Mail_Address:

metadata@disl.org

Hours_of_Service:

8-5:00 CST

Contact_Instructions:

Please email the metadata specialist for further information.

Distribution_Liability:

The Dauphin Island Sea Lab's Marine Paleoecology Lab makes no warranty regarding these data, expressed or implied, nor does the fact of distribution constitute such a warranty. The DISL: Marine Paleoecology Lab cannot assume liability for any damages caused by any errors or omissions in these data, nor as a result of the failure of these data to function on a particular system.

Technical_Prerequisites:

These data were created in Microsoft Excel. A program capable of reading these files is necessary.

Metadata_Reference_Information:

Metadata_Date:

20100630

Metadata_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization:

Dauphin Island Sea Lab

Contact_Position:

Data Management Specialist

Contact_Address:

Address_Type:

mailing and physical

Address:

101 Bienville Blvd.

City:

Dauphin Island

State_or_Province:

Al

Postal_Code:

36528

Country:

USA

Contact_Voice_Telephone:

251-861-2141

Contact_Electronic_Mail_Address:

metadata@disl.org

Hours_of_Service:

8-5:00 CST

Contact_Instructions:

Please email the metadata specialist for further information.

Metadata_Standard_Name:

FGDC Content Standard for Digital Geospatial Metadata

Metadata_Standard_Version:

FGDC-STD-001-1998

Metadata_Access_Constraints:

none