Dear Volunteer:

Thank you for your interest in monitoring horseshoe crab spawning habitat. Our interest lies in measuring population abundance and determining which areas are serving as breeding grounds. During the latter part of May through mid June, adult horseshoe crabs migrate inshore in search of sandy beach areas where they will dig nests and deposit eggs for fertilization. Optimal egg development requires sufficient tidal activity to keep the eggs moist, salinity levels of at least 8 parts per thousand, and an gentle beach slope for larvae to reach the water’s edge.
The Coastal Bays 2003 survey will be conducted over a period of twelve evenings: May 14, 16, 18, 29, 31, June 2, 12, 14, 16, 27, 29 and July 1. Sites can be monitored by individuals or by teams whose individuals cannot commit to all 12 sampling dates. Sites that have been monitored previously include:

Land Access	Boat Access
Assateague Island, north & south of Rt. 611	Isle of Wight, Wildlife Management Area
Ocean City, Oceanic Pier Bayside (inlet North Jetty)	Manklin Creek – Mocasin Pond
Ocean City 33rd Street Bayside	Manklin Creek – South of Mocasin Pond
St. Martin River, off Rt. 90 in Ocean Pines	North end of Assateague Island – 3 sites
St. Martin River, off Godfrey Bunting Road	Turville Creek
Smokehouse Cove, Isle of Wight Management Area	Holland Island, O.C. 70th Street Bayside
Mackey’s 54th Street Ocean City Bayside	Poplar Point, North of Rt. 90
Seacrets 49th Street Ocean City Bayside	Reedy Island
Mellow Beach 46th Street Ocean City Bayside
Fager’s Island

This is not to suggest that these are the only areas. On the contrary we would like to be aware of any sandy beaches that you may know of which are used by horseshoe crabs. Feel free to choose a site in your neighborhood. Be aware that Skimmer Island and certain areas of Assateague Island are prohibited due to Piping Plover nest sites, and be sure to request owner permission if you choose to monitor on private property. Instructions for the survey, a schedule of dates and times, and two graphics: one of the coastal bays watershed and a horseshoe crab classification diagram, follow this letter.
If, after reviewing all the materials, you are still interested in participating in the 2003 survey please visit your survey site to be sure it still has a sandy beach (some have been developed or bulkheaded recently). Next, either call or email me with the location specifics so I can direct other volunteers to areas that are not currently being monitored.
Again thank you for your interest in this worthwhile endeavor. Without your assistance this survey could not be conducted.


Carol J. Cain
Technical Coordinator
Maryland Coastal Bays Program
9609 Stephen Decatur Highway
Berlin, MD 21811
technical@mdcoastalbays.org
phone (410) 219-5320


Source: horseshoecrab.org ERDG.
Illustration by George Yurgin

Survey Dates and Times for the 2003 Volunteer Horseshoe Crab Spawning Survey
Maryland Coastal Bays

Tide times are based upon tables found at www.saltwatertides.com for the Ocean City Inlet. All other times are only approximated, by adding 10 minutes for the Isle of Wight Bay, add 2 hours for Assawoman and Sinepuxent Bays, and add 4 hours for Chincoteague Bay.

Watershed Evening High Tide
Sample #	Date	Moon Phase	Assawoman	Isle of Wight	O.C. Inlet	Sinepuxent	Chincoteague
1	Wed, May 14	2 days before FM	10:25 PM	8:35 PM	8:25 PM	10:25 PM	12:25 AM
2	Fri, May 16	Full Moon	12:10 AM	10:20 PM	10:10 PM	12:10 AM	2:10 AM
3	Sun, May 18	2 days after FM	1:51 AM	12:01 AM	11:51 PM	1:51 AM	3:51 AM
4	Thurs, May 29	NM – 2 days	9:26 PM	7:36 PM	7:26 PM	9:26 PM	11:26 PM
5	Sat, May 31	New Moon	10:46 PM	8:56 PM	8:46 PM	10:46 PM	12:46 AM
6	Mon, June 2	NM + 2 days	12:09 AM	10:19 PM	10:09 PM	12:09 AM	2:09 AM
7	Thurs, June 12	FM – 2 days	8:38 PM	6:48 PM	6:38 PM	8:38 PM	10:38 PM
8	Sat, June 14	Full Moon	10:25 PM	8:35 PM	8:25 PM	10:25 PM	12:25 AM
9	Mon, June 16	FM + 2 days	12:10 AM	10:20 PM	10:10 PM	12:10 AM	2:10 AM
10	Fri, June 27	NM – 2 days	8:58 PM	7:08 PM	6:58 PM	8:58 PM	10:58 PM
11	Sun, June 29	New Moon	10:23 PM	8:33 PM	8:23 PM	10:23 PM	12:23 AM
12	Tues, July 1	NM + 2 days	11:49 PM	9:59 PM	9:49 PM	11:49 PM	1:49 AM

Horseshoe Crab spawning season varies according to latitude, but it generally peaks in May and June, with the maximum spawning occurring on evening high tides during the full and new moons. The compound eye structure and photoreceptors (light sensors), on the tail enable the animals to detect the ultraviolet light of the moon. The number of crabs spawning around each lunar tide varies from year to year, but will peak in the low light around dawn or dusk while taking advantage of the higher than usual tides. Nests are deposited in the sand between the low and high tide marks on the beach. The closer the nests are to the high tide line, the more heat from the sun can be counted on to incubate the eggs.
While conditions during the evening high tide are preferred, crabs will spawn during the day as well, particularly in areas with large populations and competition for beach access is a factor. Crabs can be counted during the
daytime high tides by subtracting 12 hours from the above tide table. Just be sure to indicate AM or PM on the data sheet!

CONTENTS:

1) This sheet of instructions.
2) Date and time of survey.
3) General map of survey area.
4) Beach site sheet for recording physical information about the survey location.
5) Tally sheets for recording data.

PREPARATION FOR THE SURVEY:
Clothing and accessories

* Wear appropriate clothing for weather and wet conditions at the water=s edge. Consider sunscreen during
the day and insect repellent when needed. If thunderstorms are present do no go onto beach.
* Bring a flashlight, clipboard or hard surface to write on, and a couple of pencils and a means to sharpen the pencils.
* Shoes are a necessity. We recommend watershoes, old sneakers, or boots. Do not go barefoot.
* An accurate wristwatch is needed for recording arrival time, as well as time survey is begun and finished.

SURVEY PROTOCOL:

* Arrive at beach at least 30 minutes before survey time. Record the time you arrive in the space marked
ARRIVAL AT SITE on the Beach Site Sheet.
* Fill out the Beach Site Sheet as completely as possible. Addresses and phone numbers of each survey team member are important in case we have questions about the data. Even if the weather prevents you from doing the survey, please fill out the survey sheet with all possible information and explain why the survey could not be completed.
* As you walk to the starting location, find a stick (1 to 2 ft. long) that you can use to determine high tide. When you get to the starting location, stand the stick in the sand at the tide line. The tide line is the highest point on the beach that the water reaches. Move the stick up the beach as the water reaches higher on the beach. Begin the survey when the tide begins to recede and the water no longer reaches the stick. Record your starting time on the Beach Site Sheet where it says START OF SURVEY.

* Perform a trial pacing to determine the length of your pace. Fill in the pacing trial form and then pace off your site. Record the number of paces it takes you to walk the site on your beach site sheet

* As you walk towards the other end of the beach, count and record all horseshoe crabs within a 1 meter transect, (extending into the water 1 meter from the high tide line). A survey protocol diagram which is included on the next page which illustrates the 1 meter transect. It is helpful to use landmarks or objects to mark the beginning and end of your walk. This allows for the same distances to survey at different time and by different people.

COUNTING AND RECORDING HORSESHOE CRABS:

* The gender of an adult horseshoe crab can be determined by:
* Size - Females tend to be approximately 25% larger than males at maturity. After examining a few horseshoe crabs you will be able to differentiate males from females by sight.
* Claws - Males develop a specialized reproductive claw at maturity. This claw enables the male to attach to the female. Turn over a male and notice how the first claw is different than all the other claws. The female lacks this type of claw.
* Use the following categories to record horseshoe crabs:
* Solitary - Lone horseshoe crabs (usually males).
* Clasping pair - When the male is attached to the female. The clasping pair will either be burrowed into the substrate or swimming.
* Satellite - Male horseshoe crabs which surround the clasping burrowed pair.
* Recording clasping and satellite crabs.
* Burrowed pair or group and swimming pair.
* Record the number of males and enclose this number with a circle for each female. Sometimes it will not be possible to separate multiple spawning groups so it becomes necessary to record the multiple groups as one which may include more than one female.
* A classification and recording of horseshoe crabs diagram is on the next page.

Once you are done surveying:

* Record the time in the space marked END OF SURVEY on the Beach Site Sheet.
* Send all of the following to the address below:

* Completed Beach Site Sheet.
* Completed Tally Sheet.

This diagram illustrates that only those live crabs within one meter (approximately 3 feet) of the surf line should be counted. The final count would be 11 burrowed pairs and 2 solitary males.

Please also count the number of stranded (up-side down) and /or dead crabs as well, these do not have to be within the 1 meter transect.

If you should encounter a high number of crabs it may be easier to make tick marks on the back of one of these pages and then enter a final tally number for the number of solitary males, solitary females, burrowed pairs, etc.

Example: Males……..

Females…….

BEACH SITE SHEET

DATE:_________________________

SURVEY TEAM NAME(S) AND CONTACT INFORMATION

NAME	ADDRESS	PHONE/EMAIL

SURVEY LOCATION (BEACH NAME): please be as descriptive as possible

_____________________________________________________________________________________________

_____________________________________________________________________________________________

If available record Latitude & Longitude:____________________________________________________________

STARTING POINT TO ENDING POINT = ______________ PACES
10 Paces = _____________ feet or meters (circle one)

TOTAL ESTIMATED LENGTH OF BEACH _______________ feet or meters (circle one)

LANDMARKS OR OBJECTS USED TO DESIGNATE START_________________________________ & FINISH

POINTS______________________________________________________________________________________

DO ANY HORSESHOE CRABS HAVE VISIBLE TAGS?

Date	Tag #	Alive or Dead	Date	Tag #	Alive or Dead

OTHER OBSERVATIONS OR COMMENTS: ______________________________________________________________

___________________________________________________________________________________________________

___________________________________________________________________________________________________

May/June 2003 Beach Site/Name: ___________________________________________________________________

Dead Crabs	Total # of Females	0
	Total # of Males	0
Stranded Crabs	Total # of Females
	Total # of Males	1
Swimming pairs (clasping male &female)	Total # of Females	0
	Total # of Males	0
Burrowing pairs or groups	Total # of Females	4
	Total # of Males	8

Solitary Crabs	Total # of Females	1
	Total # of Males	4
Wave Height Striking Beach (choose:) <6 inches 6-12 inches > 1 foot	6-12 inches
Relative Amount of Natural Light (choose:) partially cloudy, mostly cloudy, dusk, moonlight, or full darkness	Moonlight
Wind Direction and Precipitation (choose:) none, light, or heavy	NE wind & Light precip.
TIME: 1. Arrival at Site: 2. Start of Survey: 3. End of Survey: Specify AM or PM !	Arrival - 8:05 PM	Start - 8:35 PM	End - 9:00 PM

Date & Moon Phase	5/14/03 FM – 2
Volunteer Name	EX: Maryland Coastal Bays Program

May/June 2003 Beach Name: _______________________________________________________________

Dead Crabs	Total # of Females	0
	Total # of Males	0
Stranded Crabs	Total # of Females	0
	Total # of Males	1
Swimming pairs (clasping male &female)	Total # of Females	0
	Total # of Males	0
Burrowing pairs or groups	Total # of Females	4
	Total # of Males	8

Solitary Crabs	Total # of Females	1				.	.	.	.	.	.	.	.
	Total # of Males	4	.	.	.	.	..	.	.	.	.	.	.
Wave Height Striking Beach (choose:) <6 inches 6-12 inches > 1 foot	6-12 inches	.	.	..	.	.	.	.		.	.	.	.
Relative Amount of Natural Light (choose:) partially cloudy, mostly cloudy, dusk, moonlight, or full darkness	Moonlight	.	.	.	.	.	.	.	.	.	.	.	.
Wind Direction and Precipitation (choose:) none, light, or heavy	NE wind & Light precip.	.	.	.	.	.	.	.	.	.	.	.	.
TIME: 1. Arrival at Site: 2. Start of Survey: 3. End of Survey: Specify AM or PM !	Arrival - 8:05 PM	Start - 8:35 PM	End - 9:00 PM		.	.	.	.	.	.	.	.	.

Date & Moon Phase	5/14/03 FM – 2	.	.	.	.	.	.
Volunteer Name	EX: Maryland Coastal Bays Program	.	.	.	.	.	.