McClellan, D.B.

Miller, M.W.

Stoffle, B.

Wiener, J.W.

Aquatic Commons

Preliminary Effort and Yield Estimates from the Haitian Fishery at Navassa Island 
 
MARGARET W. MILLER1, JEAN W. WIENER2, DAVID B. MCCLELLAN1, and BRENT STOFFLE1   
 1Southeast Fisheries Science Center, NOAA-Fisheries Service, 75 Virginia Beach Dr., Miami, Florida 33149 USA 
2Fondation pour la Protection de la Biodiversité Marine (FoProBiM) 
6011 Henning St., Bethesda, Maryland  20817  USA 
 
ABSTRACT 
Navassa is a small, uninhabited oceanic island 50 km west of Haiti. The USA has designated the island and a 12 mile marine 
radius as a Caribbean National Wildlife Refuge, but sovereignty is disputed between the USA and Haiti. Observational reports from 
infrequent scientific expeditions, 2000-2004, have predicted and noted increasing fishing effort. Transient Haitian fishers regularly 
frequent the island, but since no quantitative fishery data is available, we sought to make educated estimates of fishing effort and 
landings. Information was derived from semi-directed interviews with participants in the fishery regarding typical fishing practices 
and direct observation/measurement of landed catch from a small number of Navassa fishing trips.  
 
KEY WORDS:  Navassa, Haitian artisanal fishery, effort and yield estimates 
 
Estimados Preliminares de la Captura y el Esfuerzo de la 
Pesqueria Haitiana en la Isla de Navassa 
 
Navassa es una pequeña isla oceánica desabitada a 50 KM al oeste de Haití.  Los Estados Unidos han designado la isla y doce 
millas  náuticas marinas alrededor como Refugio de la Fauna Nacional del Caribe, pero su soberanía esta aún en disputa entre Los 
Estados Unidos y Haití. Expediciones científicas ocasionales entre el 2000 y el 2006 han  observado un esfuerzo de pesca creciente. 
Pescadores haitianos  frecuentan la isla  regularmente, pero no existen datos cuantitativos de la pesquería, por lo que se decidió 
realizar estimados de capturas y desembarcos.  La información se obtuvo mediante entrevistas indirectas con pescadores participan-
tes en prácticas pesqueras típicas y observaciones o mediciones directas realizadas a desembarcos de un número pequeño de pesca-
dores. 
 
PALABRAS CLAVES:  Navassa, pesqueria Haitiana, estimados de captura y esfuerzo 
Proceedings of the 60th Gulf and Caribbean Fisheries Institute     November 5 - 9, 2007   Punta Cana, Dominican Republic 
INTRODUCTION 
There is increasing interest in fisheries management at 
Navassa, a small, uninhabited oceanic island 50 km west of 
Haiti.  Sovereignty is disputed between the USA and Haiti, 
with transient Haitian fishers frequenting the island and the 
USA designating the island and a 12-mile marine radius as 
a National Wildlife Refuge.  Observational reports from 
infrequent scientific expeditions have indicated increasing 
fishing effort over the period from 2000 - 2004 (Miller and 
Gerstner 2002, Miller 2003, Miller et al. 2003, McClellan 
and Miller 2005).  Over this same short time frame, a trend 
of reduced reef fish abundance and size has been docu-
mented (Miller et al. 2007) via visual census (McClellan 
and Miller 2003).  Since no quantitative fishery data is 
available, we sought to make educated estimates of fishing 
effort and landings from Navassa derived from semi-
directed interviews with participants in the fishery 
regarding typical fishing practices and direct observation/
measurement of landed catch from a small number of 
Navassa fishing trips.   
 
METHODS 
In 2004 - 2005, we conducted a sociocultural assess-
ment of the Navassa fishery via on-site observations of 
fishing activities and interviews during a November 2004 
cruise to Navassa and site visits to six villages in southwest 
Haiti during March-August 2005.  We undertook semi-
directed group and individual interviews of the fishing 
communities working at Navassa in the Haitian-Creole 
language to describe fishing practices and perceptions of 
changes over time.  Interviews of fishers at Navassa were 
conducted during a November 2004 cruise by approaching 
each fishing vessel observed (30 fishers).  Interviews in 
south-west Haiti were conducted during three site visits 
(March – August 2005) and included participants from six 
villages (Figure 1).  Semi-directed interviews were held 
with individuals and small groups of fishers (90 total 
estimated participants, 53 individual interviews) following 
community meetings (c. 450 participants) to identify key 
informants with knowledge of the Navassa fishery 
(ethnographic methods detailed in Wiener 2005). Consen-
sus responses from small group and individual interviews 
are reported.  
We sought to estimate fishing effort from consensus 
average numbers of individual fishers, person trips and 
boat trips reported in interviews.  We then combined these 
estimates with the landed catch measured from three 
independent boat trips landed in two separate villages in 
May/June 2005 to extrapolate an estimate of total annual 
landings from the Navassa fishery.  Due to the numerous 
assumptions involved in such extrapolations, we sought to 
bound each step with high and low estimates related to the 
qualitative degree of uncertainty at that step. 
Finfish catch was salted and gutted with head removed 
when landed and not identifiable to taxa.  Conversion 
factors for salted/dried, gutted, head-removed finfish were 
  Miller, M.W. et al.   GCFI:60   (2008) Page 255 
 
examined from a compilation of available national 
authorities’ factors reported to FAO (FAO/Fisheries 
Circular C847 (Rev.1) "Conversion factors from landed to 
live weight"; accessed April 2007 at: 
 
http://www.fao.org/fi/website/FIRetrieveAction.do?
dom=org&xml=FIDI_STAT_org.xml&xp_nav=3,3,3).  
 
Although there were no records for reef fish species in 
this compilation, reported conversion factors for other 
species/countries with this processed form ranged from 1.7 
to 2.8.  We chose to bound our estimates for landed finfish 
using conversion factors of 2.0 and 2.5.  
Figure 1.  Relative location of Navassa Island and six 
villages in southwest Haiti where fisher interviews were 
performed.  
 
Because interviews yielded little consistency in reports 
of total number of trips per year, and because there is 
uncertainty as to how much of the year active fishing takes 
place (e.g., some fishers report a ‘resting season’ from 
December through Easter), we used a range of three 
estimates of total trips per year. The estimates were based 
on: 
i)  The consensus number of trips per year reported 
in fisher interviews,  
ii) The average 2004 observed number of boats per 
day fishing at Navassa (assuming average eight 
days per trip from interviews and, conservatively, 
six months of active fishing per year), and 
iii) The average 2002 observed number of boats per 
day fishing at Navassa with similar assumptions.  
These scenarios gave estimates of 150, 99, and 45 
trips per year, respectively.  
Area of the first shelf around Navassa (~30 m depth) 
was determined from GIS analysis of IKONOS satellite 
imagery.  Further from shore, the bathymetry drops to 
abyssal depths and most fishing activity has been observed 
in this nearshore area. 
 
RESULTS AND DISCUSSION 
The measured landings (finfish, lobster, and conch) 
from three Navassa fishing trips are given in Table 1.  
Based on interviews, these trips were typical in terms of 
number of fishers participating and length of trip.  Catch 
was variable among trips for all three catch types and did 
not relate directly to effort (i.e. person-days for the trip) as 
the trip with the highest number of person days (60) had 
the lowest total catch (though higher lobster catch). 
Estimates extrapolating these observed landings to 
annual catch and yield (catch per shelf area) are given in 
Table 2.  Based on uncertainties related to conversion 
factor (salted gutted to fresh weight for fin fish) and actual 
number of fishing trips per year, annual catch estimates 
range from 14 to 58 tons total, or 1.6 to 6.7 tons/km2 shelf 
area.   
We hope to utilize yield estimates, in comparison to 
estimates from other, comparable regions to infer the status 
of the Navassa fishery.  For example, if the areal yield is 
notably higher than comparable fisheries, this may indicate 
overexploitation that is bound to be short-lived.  Alterna-
tively, high yields may indicate a particularly high 
productivity due to unique habitat or oceanographic 
features, though the oceanic isolation and high physical 
disturbance regime of Navassa suggests this is unlikely 
(Sandin 2003).  Conversely, if the yield is low, this might 
indicate relative under-exploitation of the fishery, abnor-
mally low productivity of the area, or an existing condition 
of overexploitation and depletion..   
Unfortunately, little reliable comparable data (i.e. 
annual catch per fished area) seems to be available for 
comparable areas of the Caribbean.  We accessed reported 
recent (2000 - 2004) annual ‘capture production’ for 
marine fishes plus mollusks plus crustaceans reported to 
FAO by various Caribbean nations (http://www.fao.org/
+ Les Cayes 
Dame Marie + 
+ Jérémie 
+ Anse d’Hainault 
Port-au- Prince 
+ Tiburon 
Navassa 
Les Irois + 
Table 1.  Catch quantified from three independent boat trips landed in southwest Haiti.  
Fish were gutted, salted, and not identifiable to taxa.  The first two boats were sampled 
in the village of Anse d’Hainault, the third in the village of Dame Marie.   
  
Fish (kg 
salted, 
gutted) 
 
Lobster 
(kg whole) 
 
Conch (kg 
fresh meat) 
 
# of 
fishers  
 
# of days 
 
Boat 1 187 
 
16 
 
 
10 
 
5 
 
5 
 
Boat 2 90 
 
25 
 
 
15 
 
6 
 
10 
 
Boat 3 151 
 
6 
 
 
21 
 
3 
 
6 
 
mean catch per trip 
 
143 16 15  
 
 
 Page 256  60th Gulf and Caribbean Fisheries Institute   
 
fishery/topic/16140) and an estimate of continental shelf 
area (reported by World Resources Institute, http://
earthtrends.wri.org/text/coastal-marine/variable-62.html) to 
provide some context for our Navassa estimates (Table 3).  
Our mid range estimate of ~ 4 tons/km2 shelf area appears 
to be relatively high while our low-range estimates are 
comparable to other, nearby nations (Dominican Republic, 
Jamaica, Table 3).  It is unclear, however, on what data the 
FAO-reported catch is based.   
If a useful fishery management plan is to be 
devised for Navassa, it will be necessary to interpret the 
estimates provided here in an appropriate regional context, 
in order to infer the degree of exploitation or over-
exploitation in the Navassa fishery.  It would also no doubt 
be appropriate to invest in obtaining more reliable effort 
and yield estimates for Navassa and most other Caribbean 
jurisdictions. 
Table 2.  Extrapolated yield estimates. Range of estimated annual landings from Navassa based on A) estimated 
150 boat trips to Navassa per year from fisher interviews, B) mean daily boats observed in November 2004 (4.4) 
extrapolated at 8 days/trip for 6 months active fishing per yr, C) mean daily boats observed in 2002 (2.0) 
extrapolated similarly. Annual fish landings converted to fresh whole weight via *conversion factor of 2.5 and 
^conversion factor of 2.0 (range derived from conversion factors reported in FAO/Fisheries Circular C847 (Rev.1); 
see text).   +Yield based on estimated 8.7 km2 shelf area. 
  
Fish (est. 
fresh kg 
high)* 
Fish (est. 
fresh kg 
low)^ 
 
Lobster 
(kg whole) 
 
Conch (kg 
fresh meat) 
  
TOTAL (kg 
fresh) 
 
YIELD+ 
(kg/km2) 
 
A) Estimated annual 
landings (max: 150 trips) 
53625 42900 2400 2250  58275-47550 6698-5465 
 
B) Estimated annual 
landings (mid-range: 99 
trips)  
35393 28314  1584 1485  
38462-
31383 4421-3607 
 
C) Estimated annual 
landings (min: 45 trips 
 
16088 12870 720 675  17483-14265 2009-1639 
Table 3.  Comparison of FAO-reported ‘capture 
production’ (marine fish plus crustaceans plus mollusks) 
for other Caribbean islands. 
 
Area 
 
Total Annual 
Capture* (mt) 
 
Shelf 
Area+ 
(km2) 
 
kg/km2 
 
Antigua/Barbuda 2213 2145 1031 
 
Cuba 45279 51040 887 
 
Dominican Republic 13378 5863 2281 
 
Haiti 6900 5856 1178 
 
Jamaica 9160 5608 1633 
 
Puerto Rico 3164 5538 571 
 
US Virgin Islands 1322 1967 672 
 * Mean total annual ‘capture production’ (marine fishes plus 
crustaceans plus mollusks) reported to FAO for the years 
2000-2004 obtained via query from Global Capture Produc-
tion database of the Fisheries and Aquaculture Department 
of FAO (http://www.fao.org/fishery/topic/16140, accessed 
January 2008) 
ACKNOWLEDGEMENTS 
This study was made possible by the NMFS Southeast Fisheries 
Science Center via funding from the NOAA Coral Reef Conservation 
Program.  Christian Derosier and Davidson Dubois of FoProBiM were 
instrumental in conducting the on-site interviews in Haiti.  Thanks to 
Todd Kellison and Jim Bohnsack for review and comments and to Carlos 
Rivero for help in GIS analyses.  Work at Navassa was performed under 
Special Use Permits #2002-10 and #41529-12 from the U.S. Fish and 
Wildlife Service.  We thank John G. Shedd Aquarium and the crew of 
their Research Vessel Coral Reef II for their invaluable support and 
partnership in this work.  
 
LITERATURE CITED 
McClellan, D.B. and G.M. Miller. 2003.  Reef fish abundance, biomass, 
species composition and habitat characterization of Navassa Island. 
Pages 24-31 in: M.W. Miller (ed.) NOAA Technical Memorandum 
NMFS-SEFSC-501. 
McClellan D.B. and M.W. Miller.  2005.  Reef Status and Fisheries of 
Navassa Island. Proceedings of the Gulf and Caribbean Fisheries 
Institute 56:505-510. 
Miller, M.W. 2003. Status of Reef Resources of Navassa Island: 
November 2002. NOAA Technical Memorandum NMFS-SEFSC-
501, 119 pp. Available at http://www.aoml.noaa.gov/general/lib/
tm%115F501.pdf 
Miller, M.W. and C.L. Gerstner. 2002.  Reefs of an uninhabited 
Caribbean island: fishes, benthic habitat, and opportunities to 
discern reef fishery impact. Biological Conservation 106:37-44. 
Miller, M.W., D.B.  McClellan, and C. Begin. 2003.  Observations on 
fisheries activities at Navassa Island. Marine Fisheries Review 
65:43-49. 
Miller, M.W., D.B. McClellan, J.W. Wiener, and B. Stoffle. 2007. 
Apparent rapid fisheries escalation at a remote Caribbean island. 
Environmental Conservation 34:92-94. 
Sandin, S.A. 2003.  Reef fish trophic analysis from Navassa Island: 
Exploring biotic and anthropogenic factors. Pages 43-56 in: M.W. 
Miller (ed.) Status of Reef Resources of Navassa Island: November 
2002. NOAA Technical Memorandum NMFS-SEFSC-501. 
Wiener, J.W. 2005.  Oral history and contemporary assessment of 
Navassa Island fishermen.  Unpubl. report for the US Department of 
Commerce NOAA/NMFS.  Available at:  http:/ /
www.sefsc.noaa.gov/PDFdocs/Navassa%5FFishers%5FReport%
5FFinal%5FFoProBIM.pdf 
 
 
 
 


Preliminary effort and yield estimates from the Haitian fishery at Navassa Island

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Preliminary effort and yield estimates from the Haitian fishery at Navassa Island

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