THE 2006 DIAMONDBACK TERRAPIN
FISHERY IN MARYLAND'S
CHESAPEAKE BAY
Gerrit J. Velema and Harley Speir
MARYLAND
defartment of
naturalResources
Maryland Department of Natural Resources
Fisheries Service
580 Taylor Avenue, B-2
Annapolis, MD 21401
Fisheries Technical Memorandum
Number 35
January, 2007
Background:
The diamondback terrapin, Malaclemys terrapin, is a small, brackish water turtle, found
only along the East and Gulf Coasts of the United States of America, from Cape Cod to
coastal Texas.
Unique in being the only truly estuarine turtle in North America,
diamondback terrapin have been an important component in the history of Maryland's
Chesapeake Bay and its human inhabitants.
Terrapin are a sexually dimorphic species, with mature males and females in the
Chesapeake Bay reaching carapace lengths of at least 17cm and 24 cm (6.8 and 9.6
inches) respectively. In the Bay, female terrapin become sexually mature at about 8 years
of age, and lay approximately 40 eggs per year in low-lying sandy beaches (Morin,
1991). Eggs hatch in July and August and the young spend the first year of life in tidal
marshes.
Terrapin reproduction faces many challenges, including egg predation and a need
for a highly specific range of nesting beach habitat. Nesting beach is steadily being
removed by bulkheading and stone armoring or
lost
to Phragmites
invasion.
Compounding these pressures on terrapin survival, a fishery for this species has existed
for as long as humans have inhabited the East Coast. Native American peoples in the
Chesapeake region had been utilizing terrapin as a food long before colonists arrived.
Colonists, in turn, did not waste any time in capitalizing on this nutritional resource.
Terrapin continued to be used for food throughout the 17th and 18th centuries by both
colonists and slaves.
Following the civil war, diamondback terrapin emerged as a
commercially important species as terrapin soup became a delicacy among the most
privileged members of 19th century society (Morin, 1991).
Regulatory History:
Although obviously a reptile, terrapin are defined in law (Natural Resources
Article 4-101, Annotated Code of Maryland) as fish. "Fish means finfish, crustaceans,
mollusks, and amphibians and reptiles which spend the majority of their life cycle in
water and any part, egg, offspring, or dead body of any of these species." In §4-202 of
the Code, the Secretary of the Department of Natural Resources is responsible for
"conservation management of the fish, fisheries, fish resources and aquatic life within the
State." The modern day Fisheries Service of the Department has had terrapin regulatory
responsibility for three decades.
Beginning in the late 1800's, Maryland's state legislature began to pass laws
governing the harvest of terrapin. Harvest was limited to Worcester County in 1868, St.
Mary's and Anne Arundel counties in 1870, and Dorchester, Kent, and Queen Anne
counties in 1872. Finally, in 1878, more comprehensive laws were passed which dictated
a minimum plastron (bottom shell) length limit of 5 inches, a closed season from April 1
to November 1, and a stipulation that terrapin eggs may not be possessed or tampered
with. These laws effectively provided a fishery for residents of tidal water counties. This
provision was eventually relaxed to include all state residents (Morin, 1991). These
general categories of restrictions have been kept in place until the present day (Table 1).
Page 1 of 11
Table 1. History of laws and regulations controlling diamondback terrapin harvest in Maryland. 1878-2006.
Year
!
Law or
Regulation \
i
Closed
Season
i Min.
|
Plastron
i
„ Length
„.
I_County
\
!Exceptions i
i
i
Pets
\
; ^
i
[Changes i
i
1878 -1879 Law
4/1 -11/1
5"
no
may not possess,
destroy, or disturb
terrapin eggs
no mention
of pets
1880-1928 Law
4/1 -11/1
5"
yes
may not possess,
destroy, or disturb
terrapin eggs
no mention
of pets
county
exception
1929,1973 Law
4/1-10/31
5"
no
may not possess,
destroy, or disturb
terrapin eggs
no mention
of pets
season
1973
Lawpasses in 1973 requiring LICENSE toharvest Diamondback terrapin. Also, mandated the adoption
ofREGULATIONS, finallyimplemented in 1975.
1974
Law
4/1 -10/31
5"
no
may not possess,
destroy, or disturb
terrapin eggs
no mention
of pets
license
required
1975 -1976 Regulation
4/1-10/31
5"
no
may not possess,
destroy, or disturb
terrapin eggs
may keep
up to 3
terrapin as
pets,
regardless
of season
or size
pets
:1877 -1981 Regulation
2/1 - 5/30
5"
no
may not possess,
destroy, or disturb
terrapin eggs
may keep
up to 3
terrapin as
pets,
regardless
of season
or size
season
1982-1991 Regulation
NONE
6"
no
may not possess,
destroy, or disturb
terrapin eggs
may keep
up to 3
terrapin as
pets,
regardless
of season
or size
season
/size
1992-2005
|
Regulation
5/1 - 7/31
6"
no
may not possess,
destroy, or disturb
terrapin eggs
may keep
up to 3
terrapin as
pets,
regardless
of season
or size
season
2006
\j^ww20Q$m
:TerrapinWash
season, chan\
quiresDNRto adopt regufat
r,forttJhW®% 2006regule
qessize limit to slot limit
tons Gonsisteni
itions require h
?with recommendations bytheMgry
arvester permits, monthly reports;
PSS" " !
shortens !
2006
Regulation
11/1-7/31
4" - 7"
no
may not possess,
destroy, or disturb
terrapin eggs
may keep
up to 3
terrapin as
pets,
regardless
of season
or size
season
/size
/permit
Page 2 of 11
From 1880 to 1928, various exceptions in size and season were made for several of
Maryland's counties. In 1929, the closed season was modified to end on October 31 instead of
November 1. In 1973, a law was passed that required all commercial terrapin harvesters to
have a license. That same year Natural Resources Article 4-903, Annotated Code ofMaryland,
was passed and authorized the Department to adopt harvest and conservation regulations,
which were first implemented in 1975.
The 1975 regulations set season and size limits and also allowed people to keep up to
three terrapin as pets, regardless of size or season. Over the next three decades, several
changes were made to the season and size limits of the terrapin fishery. From 1977 through
1981, the closed season extended from February 1 through May 30. From 1982 through 1991,
there was no closed season at all, and the minimum plastron length was changed to 6 inches. A
closed season was finally imposed again in 1992, extending from May 1 through July 31.
These closed season dates remained unchanged until 2006.
Changes made in blue crab regulations, however, had direct effects on terrapin
mortality in fishing gear. Regulations effective in January of 1999 required all recreational
crab pots to be equipped with a turtle reduction device (Code of Maryland Regulations
[COMAR] 08.02.03.07B). These regulations are still effective in 2007.
In 2006, the Maryland General Assembly passed a law "...requiring the Department to
adopt regulations governing terrapin resources and the catching of terrapin consistent with
certain recommendations of the Maryland Diamondback Terrapin Task Force..." Effective
August 1, 2006, an emergency regulation was put into place, creating a plastron slot length
limit for terrapin from 4 to 7 inches as well as a new closed season from November 1 to July
31 (COMAR 08.02.06.02).
These regulations, which became permanent during the 2006 fall season, also require a
person to hold a valid terrapin harvester permit in order to harvest terrapin during the open
season. The goal of this new permit program is to improve reporting of terrapin harvest.
Fishermen who possess a valid 'Conch, Turtle, Lobster License' (CTL) or an 'Unlimited Tidal
Fish License' (TFL) are eligible to receive the terrapin harvester permit. For the 2006 terrapin
season, a total of 34 permits were issued. As each application was received and processed,
permittees were given one permit card for each month or partial month remaining in the
season. Only 22 permittees applied early enough to have access to all three months of the
season. Six permittees, on the other hand, applied very late in the season, and received a
permit card for the final month only. A total of 84 monthly permit cards were issued for the
2006 season.
Harvest Summary:
i: Historical harvest data from fisherman reports:
Maryland licensed commercial fishermen are required to report their harvest of all fish, crabs,
shellfish and turtles on forms provided by the Department. Commercial catch records for many
Chesapeake Bay species date back 100 years. Over the past four decades, terrapin harvests
have ranged in size from a reported 7800 pounds in 1966 to two pounds in 1999 (Table 2).
Over the past eight years, at least one person, and up to as many as nine people, has reported
harvesting some amount of terrapin each year.
Page 3 of 11
Table 2
reports
. Historical diamondback terrapin harvest data reported on Maryland catch
from 1962 - 2005. Years with no reported catch have been omitted.
••••
Rounds WMiKM
Pounds wmmmmBIlllllWiiiMI
PMllft
4000 li^fllfl
1400 SIMIII!
41
IlllBil
7600 nm
1800 immmi
345
•Mill
7400 mn
i
5100 IHIIlii
80
lull!!!
5500 LidTsr
!
1200 iHKm
348
BsiPv^^MWj
7800 immmm
400 iiaiiiiii
343
llllllil
5900 •Mill
200 mw
2
MllWttiSIl
5200 iraum
3600 isiiisii
28
HMHl
1400 MSlflli
6101 llfBiilrt
211
iMiiii
3300 Siiisiil
658 wsm^m
676
IMlllll
5100 [m» __. j
3500 Boo^^Tn
2622
IBIillf
4200 [1955
]
1125 iiisgBil
760
ii: Permit Card Data:
From January through April 2006, terrapin were still harvested under old regulations that did
not require a permit. Harvest was not reported by permit until the new regulation became
effective in August of 2006. Of the 84 monthly terrapin harvester permit cards issued for 2006,
a total of 76 cards were returned as of January 23, 2006 - a 90% level of reporting (Table 3).
Of those permit cards returned, a total of 26 monthly cards from 14 permittees have reported
catch. These successful permittees fished for a total of 226 days, and harvested a total of
10,278 terrapin (17472.61bs) f (Table 3).
Table 3. Summary of permit card data for Maryland's 2006 fall terrapin season
number
34
number of permittees reporting catch
14
number ofmonmly permit cards issued
84
numberofmonmly permit cards returned (as of01/23/2006)
76
% returned (as of 01/23/200,6)
90%
number of returned permit cards reporting catch
26
% of returned permitcards reporting catch
34%
Total days
for those reporting catch
226
Total hardest (number)
10278
Total harvc
17472.6
Average
reporting catch (number)
395
Average haivest per peirnit card reporting catch (Ibsf
672.0
Average harvest per fishing day (number)
45
Average haryest per fishing day (Ibsr
'~1
77.3
assumption: 1 terrapin = 1.7 lbs
f Note: Values inparentheses, following a numberor weight ofterrapin have been calculated
using theformula [J terrapin = 1.7 lbs] based on 2006 permit card data reported using both
weights and numbers (AppendixA).
Page 4 of 11
The average harvest from only those permit cards reporting catch was 395 terrapin (672 lbs)
per card, or 45 terrapin (77.3 lbs) per successful fishing day (Table 3). Total individual harvest
reported on permit cards ranged from 18 terrapin (30.6 lbs) to 2678 terrapin (4552.6 lbs). Of
the 14 permittees that reported harvest, 11 people had not reported harvesting terrapin during
the preceding two and a half years.
Permit card data indicates highly variable levels of harvest among fishermen. Only two
permittees harvested over 2000 lbs of terrapin during the 2006 fall season, while seven others
each harvested less than 1000 lbs (Table 4). There was also a skew in terms of the geography
of the harvest. All of the harvest of terrapin during the 2006 fall season took place on the
eastern side of the Chesapeake Bay. The smallest harvest, 3 terrapin (5.1 lbs), took place in the
Chester River, while the greatest catch, 2155 terrapin (3663.5 lbs), occurred in the Nanticoke
River (Figure 1).
Table 4. Total harvest reported by harvesters during Maryland's 2006 fall terrapin season.
W^M§ Number of Terrapin Harvested
||i^^
ggjg§|
W$kI-i$'PM{
18
30.6
W:^;M\^M; /!
68
115.6
MMSMM
94
159.8
175
297.5
KSSliH
294
499.8
i#L'' v :~:±J
443
753.1
»a£;^j
757
1286.9
m^m&M
529
899.3
m&?i&^
644
1094.8
mrnmm
796
1353.2
mfimmM'i
846
1438.2
mw-mm
892
1516.4
m^xMi
2044
3474.8
2678
4552.6
iiffiOT&&^,:^ IS^^'MMM^^^aiiffi^^ Li':: ••
•'•/• ••'•••••-••:
•:--!
•'
•• •'
'!"••
'••'
/'•!
•'•'."
••
••
'•:.
••
'''•••',
.'!•
•••
•••!,.';'!.'.-'.
•:.•'••:'•
•!'
.'•
'•".- '^
'•'
•••:'.i'i
•", •v: >. J.iV "• •"•-."
•"."::"
Vi =" •"•!" -•"-•"•
••" MB&IMiil
* assumption: 1 terrapin = 1.7 lbs.
iii: Dealer Data:
Information on the terrapin fishery has been gathered from data submitted to the Department
by licensed seafood dealers. Dealers report species purchased from Maryland fishermen. In
comparisons of fisherman catch reports and seafood dealer reports over the same time period,
dealer data appear to be more complete in most years (Table 5).
Seafood dealers are authorized to both purchase and resell terrapin. Harvesters of
terrapin are not required, however, to sell their catch to a dealer; there are other non-dealers
who may purchase terrapin. For example, some terrapin are sold to aquaculture businesses that
raise terrapin in tanks and ponds. Terrapin harvesters may also sell their catch directly to
restaurants. As a result, past harvest data from dealers have more than likely been incomplete,
as they were based solely on their purchases from fishermen.
One would expect fisherman-reported catch levels to be relatively higher than dealer
reports.
Page 5 of 11
Figure 1. Geographic distribution of harvest during the 2006 fall terrapin
fishery in Maryland's Chesapeake Bay.
SUSOUEHJUWA RIVER 090
SUSQUEHANNA FLMTS 089
BUSHRIVER VBjf
"in
GUNPOWDER Rim 045 A
MIDDLE RIVER 059
BACKRJVERtm
RIVER OM
ELKRIVER 041
NOTE: Several permit cards neglected to indicate the NOAA code in which their
terrapin were harvested. These permit cards contained a total of 1172 terrapin (1992.4
lbs)
Page 6 of 11
Table 5. Comparison of diamondback terrapin harvest reported in Maryland dealer reports and
fisherman catch reports from 1998 through 2005.
1
4^^^^^^^^^mmmmmmnmmi^^^m^^mMaaam
ImllllwIiiiil^iililllllllllBMIB iiliilB^ffli^HHiiiiH^BIBiJISSllI
i!i5iS
..
_. _ ~3T1
89
343
i§M
.
i
320
2
imt$[ _~
~~ i
0
28
:2ftt^
' v" „ i
0
0
iMsm ^
i
378
211
:.»!•_.
.7 „.
~:l'i
2373
676
2§g$*L
1
14665
2622
2005
'
1
9020
760
* assumption: 1 terrapin = 2.5 lbs
Prior to August 1, 2006, there were 14 complete years in which terrapin were
harvested for nine months per year (Table 1). The dealer data for 2006 shows harvest
from January through April (before the new regulations were effective) and August
through October (under the new regulations). Although there are likely some delinquent
reports yet to be sent in to the Department, dealer data thus far indicates only 7366 lbs of
terrapin have been sold to dealers in Maryland in 2006 (Table 6).
Table 6. Dealer purchase summaries for the Maryland diamondback terrapin fishery from 2004 to
2006.
2004
j !
2005
] L._L
2$M
I
j ©iateiJfc
a*
:
Ififipf i
Weight
i lis i
!
i
iPriee/lb
m
•
i Weight
0$ |
£ale: # of I
I
1
iVVgptJ j
i fife
Price/lb.
i&^ML-J
840
2100
2.5
648
1620
2.5
260
650
2.5
February
\
200
500
2.5
0
0
60
150
2.5
jMa&l ^_~]
613.6
1534
2.46
2250
5625
1
186
464
2.52
$M\
;
1525.2
3813
1
10
25
1.2
226
566
2.5
Mz&
!
0
0
0
0
0
0
IrJiiMei
J
600
1500
0.9
0
0
0
0
LiliL
:
0
0
0
0
0
0
Ungual _. _t
190
475
2.78
100
250
3
576 *
980 +
1.2
LiSMtgE&Mi^
240.8
602
2.88
120
300
2.5
2174 +
3695 f
2.63
'j^io^BP
496.4
1241
2.52
180
450
2.5
506 f
861 f
3
November
0
500
2.5
0
0
0
0
liiseimfc'
0
2400
2.5
0
750
2.5
0
0
jam.•MM
14665 WM3&&Bil^ll
9020 lillili ft;liawl 7366 f HW
* assumption 1:1 terrapin = 2.5 lbs
**assumption 2: 1 terrapin = 2.5 lbs before August; 1.7 lbs after August.
r2006 Dealer data is incomplete - reports have notall been received at timeof publishing
Even allowing for further reporting for 2006, it is unlikely that the dealer data for
2006 will look significantly different from that of 2004 or 2005 (Table 6). When the
2006 dealer data corresponding to the fall (August 1 - October 31) harvest season is
Page 7 of 11
compared to data collected from permit cards for that period, a large discrepancy can
easily be seen (Table 7). The dealer data for the fall harvest season was provided by two
seafood dealers. Permittees, on the other hand, reported selling to five different entities,
including these 2 dealers, 1 non-dealer, and two other dealers who have not yet reported.
These dealers are required to report by the time they apply for a renewal of their license.
Reporting is mandatory, and a license will not be renewed until all reports are submitted.
Table 7. Dealer data and permit card data for Maryland's 2006 fall terrapin season.
MONTH
Dealer Data
3
Gale. # of Terrapin*
^Bliatttifl^L^]
Permit Card Data
Jin Mii^s^ili#
August
576
980
5123
8709
September
2173
3694
4211
7159
October
506
861
944
1605
TOTALS
111
$256
5535
* assumption: 1 terrapin = 1.7 lbs
f 2006 Dealer data is incomplete - reports havenotall been received at time of publishing
Although permit card data for the new 2006 terrapin harvest season is much
higher than the dealer data for the same period, this does not necessarily indicate that
more terrapin were harvested during 2006 than the previous two years (Table 6; 7). The
new regulations have provided more complete reporting through the permit card system.
In the 2006 fall season, harvest data from permit cards is more complete than dealer data.
iv: Combined Data:
For the portion of the year prior to the new regulations, data is currently available from
fisherman catch reports, as well as dealer reports. Fisherman catch reports during this
period of time indicate a harvest of 370.5 lbs, while the dealer reports indicate a harvest
of 1830 lbs (Table 8). It is clear from this comparison that dealer data indicates a greater
harvest, and thus is more complete for this portion of the 2006 harvest season.
Table 8. Harvest of diamondback terrapin in Maryland by month from fisherman catch
reports and dealer reports from January through July, 2006.
MONTH
!
l
ijeali?Dafei
j!
Fisherman Gatch. ;if^pMfaMi^ J
1Majtefl!?fcsllfi* [ m\ r
•
•
W0mIM;;
\$&(ffltet
J
260
650
88
220
LMaiaB
J
60
150
35
87.5
WaM.
~
J
186
464
0
0
!-i§i8riL"_"._:_.-""_J
226
566
25
63
May
._
J
0
0
0
0
i June
0
0
0
0
July
•
0
0
0
0
[Msiyll „_LJ • WmaKiSmlmm
1830
4M SillllllMffilll
assumption: 1 terrapin = 2.5 lbs
Page 8 of 11
In order to get a total harvest number for 2006, it is necessary to utilize data from the
January to July segment of the season. Since dealer data is likely more complete than
fisherman catch report data, it will be used to summarize the 2006 terrapin harvest prior
to the implementation of the new regulations in August. When the dealer data is
combined with the permit card data from the fall terrapin harvest season, the data
indicates a total terrapin harvest of 19,303 lbs (11,010 terrapin) for 2006 (Table 9).
Table 9. Harvest of diamondback terrapin in Maryland by month from harvester permit
card reports (August - October), and from dealer reports from January to July, 2006.
|||Mpinr^,,:
G;00
Data
Might
Permit CardjData
Terrapin
Combined Data
Wfeifit
Januarys
260
650
it*
260
650
February
60
150
60
150
March
186
464
186
464
226
566
226
566
CLOSED
CLOSED
il@li®$§Ef( rcns
CLOSED
CLOSED
I
IJWJJ''
CLOSED
CLOSED
1
^f®l£©Sffi;!
CLOSED
CLOSED
CLOSED
CLOSED
i&MfliS!
l'rt'4®
CLOSED
CLOSED
itit^JMl siliiiiiiS
980
5123
8709
5123
8709
ISe'ifegrjfeBrl lii^Mi
;3§S5;
4211
7159
4211
7159
PW
M
October
ii['OiiiiiWn/SiBs',;
im
944
1605
944
1605
tNbyjerniiil ifMlisiip
|@|fc@SEE);!
CLOSED
CLOSED
CLOSED
CLOSED
December IfilMiEEii M0SE0;:
CLOSED
CLOSED
CLOSED
CLOSED
tmmmmiM
3988
$m\
10278
19303
* assumption: 1 terrapin = 2.5 lbs before August; 1.7 lbs afterward.
f 2006Dealer data is incomplete - reports have notall been received at time of publishing.
Implications for 2007 Management:
Some observations made during the 2006 terrapin season will have implications
for management of the 2007 terrapin harvest season. One management challenge for the
terrapin fishery is a large time lag in reporting. Delinquent reporting of fisherman catch
reports and permit cards makes it difficult for managers to assess the outcomes of
previous decisions and make appropriate modifications for short term management. As
specified in Maryland regulation, non-reporters from the 2006 permit program will not be
approved for a terrapin permit for the 2007 season.
Another problem encountered during the 2006 terrapin season is incomplete
reporting. Permit cards for 2006 were designed with space for both weight and numbers
of terrapin to be recorded. Only one of the harvesters filled in both columns on the
permit card.
In future seasons, reporting both weight and numbers should be made
mandatory in order to improve the usefulness of the data collected. It may also be useful
to include a column for gear type to be recorded.
Page 9 of 11
The new regulation requires applications for terrapin harvest permits to be
"received between June 1 and July 31 of each calendar year" (COMAR 08.02.06.02).
During the fall terrapin season, applications for permits were accepted throughout the
season because the regulations did not become effective until the starting date of the
season. This exception to the regulation provided everyone an equal opportunity to apply
and participate in the fishery. Applicants for the 2007 terrapin fishery will be restricted to
the two month application window specified in regulation, thus giving all permittees
equal access to all three months of the season.
In managing Maryland's diamondback terrapin fishery, it is very important to
keep a close eye on the outcomes of the harvest season. Quality data, good reporting, and
open lines of communication between harvesters and managers are all vital components
of this monitoring effort. Our hope is that this vigilance will allow Maryland to continue
to manage its resources as effectively as possible and maintain a healthy population of
terrapin in the Chesapeake Bay that all Marylanders can enjoy.
Page 10 of 11
Appendix A:
A new formula for the calculation of terrapin weights during the 2006 August-October
harvest season.
Dealer data has previously been reported in weights (lbs), while most permit card data is
reported as numbers of terrapin. Fisheries Statistics has used a standard terrapin weight
of 2.5 pounds per terrapin in their database to convert any dealer data reported as
numbers of terrapin. This weight is based on a terrapin harvest under the 6" minimum
size limit. All calculations in this report prior to the fall 2006 season, converting between
terrapin numbers and weights, used this formula.
One permittee in the 2006 diamondback terrapin harvest season, however,
reported harvest both as weights and numbers.
This permittee provided this dual
information for 9 days of harvesting, allowing an actual calculation of the average weight
of terrapin (Table 9).
Beginning in the August 2006 season, the minimum size was reduced to 4 inches
(slot of 4-7 inches) from a minimum of 6 inches. The smaller average weight may
indicate a selection of smaller individuals in the fishery.
In fact, a phone conversation
with one dealer indicated that much of the harvest he was dealing with was of smaller
males. This data indicates that a more realistic average weight during the August to
October season is 1.7 pounds per terrapin. This conversion number was used in this
report for calculations that used data from the 2006 fall season.
Catch data from permittee reporting both weight and number for daily harvest during the
Maryland August-October, 2006 diamondback terrapin season.
! Daily CatchSample #
jIMHttKffiiL j Number of Terrapin
AverageWetght
i
"_
;
. .
i
34
15
2.27
r~r~"*f::z.;~"i
29
6
4.83
L
~&
~!
1
1
1.00
r
."". :~m::: .. m
1
1
1.00
. 11 .in-:
i
35
25
1.40
r".i:""";nji:i:i;;j
12
7
1.71
1
y~lr!J "1 ' 1
24
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