Manatees in French Guiana 2015

POPULATION SIZE, DISTRIBUTION AND CONSERVATION ASPECTS OF THE MANATEE Trichechus manatus manatus IN FRENCH GUIANA

FINAL REPORT

Prepared by

Dr. Nataly Castelblanco-Martínez

Presented to:

Parc National de la Guadaloupe

March 2015

Manatees in French Guiana 2015

Content

1 BACKGROUND ...... 2 2 OBJECTIVES ...... 3 3 AREA OF STUDY ...... 3 4 METHODS ...... 5 5 DATA ANALYSIS ...... 9 6 RESULTS ...... 11 6.1 Effort ...... 11 6.2 Survey conditions ...... 16 6.3 Evidences of manatee presence ...... 17 6.5. Conservation state ...... 32 7 DISCUSSION ...... 36 7.1 Methodological constrains ...... 36 7.2 Spatial variation ...... 37 7.3 Temporal variation ...... 37 7.4 Abundance, distribution and conservation ...... 38 8 CONCLUSIONS ...... 39 9 RECOMMENDATIONS ...... 39 APPENDIX I. Interview Form ...... 43 General data of the interviewee ...... 43 Part 1: Knowledge of the species ...... 43 Part 2: Distribution areas and habitat use ...... 43 Part 3: Seasonality of sightings ...... 44 Part 4: Sightings and evidences ...... 44 Parte 5: Ecology ...... 44 Parte 6: Conservation ...... 45 APPENDIX II. Online survey ...... 46

Manatees in French Guiana 2015

1 BACKGROUND

Antillean manatees Trichechus manatus manatus are aquatic mammals considered endangered according to the IUCN Red List of Threatened Species (Self-Sullivan and Mignucci-Giannoni 2008). Manatees face similar threats throughout their range, which include habitat degradation and loss, watercraft collisions, incidental catch/accidental take in fishing gear, pollution, human disturbance, natural disasters, and hunting. In French Guiana (FG), an administrative unit of France, preliminary interview surveys suggested that manatees are still present and regularly sighted all along the coast and up to 80 km inland, but may be less abundant than in the recent past (de Thoisy et al. 2003). As the alluvial coastal plain is quite narrow, their habitats are naturally restricted. The manatees are also encountered on nearby rocky shores (Cayenne Island, Malmanoury, Ilet-la-Mère and Rocky point at Kourou) and in some large rivers such as the Maroni, the Approuague and the Oyapock. The relatively pristine state and quietness of some estuarine areas may play a major role in the suitability of habitats for manatees (Artigas et al. 2003). Direct threats, such as hunting for meat and for local customs, appear to occur at only low levels. There is a general disinterest in hunting amongst younger people, and the traditional sacred status of the species may help to prevent illegal hunting in some areas (de Thoisy et al. 2003). At the moment, their secretive behaviour, fairly undisturbed estuarine habitats, and protection laws create an optimistic outlook for the future of the manatees in French Guiana (Artigas et al. 2003).

Between 28/March/2012 and 13/April/2012 we visited the area of study, in order to recognize the ecological scenario where manatees inhabit, and therefore to acquire elements to properly design a suitable methodology for long-term manatee monitoring (Castelblanco-Martínez 2012b). The manatee presence was confirmed by feeding areas and sightings. This first visit confirmed that manatees still inhabit most of the coast of French Guiana, and apparently the encounters with the species are relatively frequent. (Castelblanco-Martínez and de Thoisy 2012). Therefore, a long-term project based on a multi-approach methodology was proposed (Castelblanco-Martínez 2012a).The present report summarizes the results obtained during the manatee survey in French Guiana, occurred during dry season and rainy season (2013-2014) in conjunction with governmental actors and the NGO Kwata.

Manatees in French Guiana 2015

2 OBJECTIVES

Main Objective

To evaluate the current status, distribution, abundance, threats and viability of the Antillean manatees population in French Guiana

Specific Objectives

 To determine the effective distribution area for the manatee population in FG and preferred habitats using complementary methodologies.  To assess the minimum population size of the manatee population inhabiting FG; and the proportion of calves.  To determine human and natural factors threaten the survival, health, or reproduction of manatees.

3 AREA OF STUDY

French Guiana, the largest French over-sea department, is situated on the north- east coast of South America between 2° - 6° latitude North and 51° - 55° longitude East (see Map 1). It belongs to the equatorial zone of the northern hemisphere. The border with Surinam is marked by the Maroni River, the French Guiana-Brazil border by the Oyapock River (Fig. 1).

Marine biodiversity in French Guiana is strongly influenced by the waters of the Amazon River, which constitute a major structuring factor for the estuarine, coastal, and shelf marine ecosystems. Moreover, the marked seasonal and inter-annual variability play important roles in the stability or fluctuations in the environmental parameters that influence biodiversity at the ecological, population, and genetic levels of aquatic organisms (Artigas et al. 2003). The climate is equatorial and therefore characterized by a wet and a dry season, and a maximal variation of the average temperature of 2° Cover the year (Spiegelberger 2002). There are two periods of high rainfall, May - June (the principal one) and January- February (secondary). The dry season lasts from July to December when stable south-eastern trade winds are dominant. The flow of the rivers of French Guiana is similar to that of the rainfall being maximum in May-June and

Manatees in French Guiana 2015 minimum generally in November, when the flow rate of the Amazon River is considerably lower. The tide in French Guiana is semidiurnal, with amplitude of up to 2.5 meters (spring tides, mesotidal regime). The coastal waters are highly turbid, and extensive mudflats occur and migrate along the coast (Artigas et al. 2003). Small streams (from headwaters to rivers with depth < 1 m and width <10 m) represent 70% of all running waters in FG. Most of small streams are located in forested areas and exhibit high ecological quality; some if not most of them have never been impacted by any human activity (Dedieu et al. 2014).

In Coswine swamps, water parameters were similar to those described in other studies: water depth varied from 2.5 m to more than 20 m; water temperature was between 24.5 °C and 30.3 °C and pH varied between 5.5 and 6.9. Salinity was low (0.0‰ to 1.3‰) with 86.9% of all samples taken in fresh water. No submerged aquatic vegetation was found in the study area. A botanical survey along the banks revealed that most plants seem to be potential forage for manatees. Red mangrove is very abundant throughout the area. It is suggested, therefore, that manatees graze on the bank vegetation, where feeding traces were found, or leave the area to feed (Spiegelberger and Ganslosser 2005).

Figure 1. French Guiana

Manatees in French Guiana 2015

4 METHODS

In French Guiana, manatees are distributed mainly in coastal environments, estuaries, rivers and floodplains characterized by low water transparency, dense forest canopy and water level changes. These facts, and the secretive behavior of the manatee, have made difficult to follow and observe the species. We used a multi-approach methodology to detect and count the individuals. All those methods are noninvasive, meaning a minimal disturbance to the animal. The distribution region was divided in nine main areas (units), covering estuaries, beaches and rivers (Fig. 2). Those areas are located in altitudes lower than 200 meters above sea level. In general, we covered all the coastal area of French Guiana (approx. 330km of coastline), and up to 80 km upstream the rivers.

Figure 2. Areas of survey in French Guiana. 1) Coswine, 2) Mana, 3) Iracoubo, 4) Sinnamary, 5) Kourou, 6) Cayenne, 7) Kaw, 8) Approuague and 9) Oyapock

Manatees in French Guiana 2015

Each area was treated separately, but following the same field collection methods and approximately the same effort in time (Table 1). It was proposed to cover the area during three sessions, each of them with an approximate duration of 4 weeks. In order to guarantee the cover of each unit, two days per session per unit were suggested, although in some cases it was possible to cover the area in only one day. In total, it was expected to conduct up to 54 field trips (days). Additional days were necessary to complete interviews and during translocations to study areas.

SESSION 1 SESSION 2 SESSION 3 Unit Day 1 Day 2 Day 1 Day 2 Day 1 Day 2 1 Coswine Oct Oct Nov Nov Dec Dec 2 Mana Oct Oct Nov Nov Dec Dec 3 Iracoubo Oct Oct Nov Nov Dec Dec 4 Sinnamary Oct Oct Nov Nov Dec Dec 5 Kourou Oct Oct Nov Nov Dec Dec 6 Cayenne Oct Oct Nov Nov Dec Dec 7 Kaw Oct Oct Nov Nov Dec Dec 8 Approuague Oct Oct Nov Nov Dec Dec 9 Oyapock Oct Oct Nov Nov Dec Dec Table 1. Proposed sampling design

However, due to logistic problems (mainly bad weather that made some field trips impossible to conduct, and additional uncontrolled situations), field surveys were conducted during dry season and early rainy season (October/2013 to April/2014.).

The main research method used consisted in boat-based strip transects sampling at slow speed (4-6 km per hour) (Fig. 3). Due the extension of the area and aiming to increase the efficiency of the survey, strategic transects were selected according to navigability characteristics and suitability of habitats for manatees. Areas with high current speed were discarded as this factor may interfere with the detection ability of the sonar and also because they were considered as unlikely used by manatees. Likewise, surveys were conducted in the middle and low section of the rivers (less than 40km from the mouth), since, according with exploratory surveys, the upper part of the rivers are rarely used by manatees. During surveys in narrow rivers (width < 50 m), transects were conducted following the middle and deepest area of the watercourse. For wider

Manatees in French Guiana 2015 rivers, one of margins was selected, and the boat was maintained at approximately 20 m from the shore.

Figure 3. Manatee boat-based survey in Kaw River using a Side-Scan Sonar (SSS).

Manatees were detected visually or by using Humminbird 997 SI COMBO Side- Scan Sonars (SSS). The SSS allows capturing images of the bottom structure and water column, providing instantaneous information on type of bottom, vegetation, depth, velocity and location. Once a potential manatee was detected by the SSS, we captured the image with all the associated information. Immediately, we turned back and passed over the position at same speed and trajectory to discard unanimated objects that could be mistaken for a manatee. If the suspected object moved away or changed its position, we considered it as an animal and waited for additional clues of manatee presence. In

Manatees in French Guiana 2015 some areas such as very meandric rivers, the silent waiting was considered unproductive since the manatee could leave the visual area very easily. A 100% positive record was defined when the manatee was spotted before, during or after the SSS detection. Otherwise, the images were analyzed a posteriori to detect manatees based on shape; size and position (see data analysis section). Images from the SSS were randomly captured at approximately every 10 min aiming to record depth, bottom conditions, speed, and coordinates.

Additional to boat transects, quick but highly efficient surveys in key spots (typically known as ‘fixed points’) were established in order to detect manatees. Typical surveys in fixed points were conducted from a small boat anchored, and included at least 4 observers. Once anchored in position, observers searched for manatees in a 360° circle around the boat. Additional fixed point surveys were conducted from the shore, form a high position as a hill or a rock. Indirect records - understood as signals of the manatee presence like feeding signs or excrements- are also recorded. A survey was defined as the transect covered with the sonar, with an exact time and position of beginning and ending, or as the silent waiting in a fixed point. Observations were made of typical manatee feeding signs on leaves and stalks on macrophytes communities, which are easily distinguishable by experienced observers.

The boats traffic was also recorded simultaneously during the manatee surveys, in order to obtain a Boat Disturbance Index, BDI (Castelblanco-Martínez 2004). Every vessel observed in the area was classified according with its engine power as follow: 1= Vessels without motor (Kayaks, canoes); 2= Vessels with small outboard engine (5 – 50 HP); 3= Vessels with medium outboard engines (55 – 200 HP); 4= Large ships with diesel motors. Lastly, interviews with inhabitants sharing habitat with manatees, especially fishermen, were developed (Fig. 4). Although the interviews tried to be informal, a list of aspects was approached as explained in the interview format (Appendix 1). Special emphasis was made in the section of distribution and threats.

Manatees in French Guiana 2015

Figure 4. Interaction with local community

5 DATA ANALYSIS

Effort. The searching effort was estimated in time (min) for the fixed points, and in time (min) and distance (km) for the boat surveys. With the objective of standardizing the effort in terms of proportion of river surveyed, transects were recreated in ArcMap by creating trajectories between the beginning and ending point of the boat survey, and following the main course of the river.

Relative abundance. The author made a first review of the images classified as ¨moving objects¨, and selected potential manatee captions based in shape, form and size. For this purpose, the images were compared with positive manatee SSS images captured by previous researchers. Also, images captured in odd survey conditions were eliminated, for example, images taken at 0km/hr or in depth less than one meter. The selected images were then organized and placed as a catalog. A blind, peer-review online system was created, and several international experts in SSS imaging applied to manatee research were invited to participate. The researchers were kindly asked to analyze and score each photo with a value ranking from 0 to 5 according to the criteria

Manatees in French Guiana 2015 detailed in Table 2 (see Appendix 2). The survey also collected basic information on the researchers’ activity, as well as time and type of experience in the use of SSS for manatee detection. Additionally, the reviewers had the opportunity to add comments and to suggest additional reviewers. The scores were transformed arbitrarily in confidentiality values (%CV) according to Table 2, and an average of CV was produced for each image. Photos with an average of CV lower than 0.6 were not considered as manatee evidence and discarded from the analysis. Photos recorded simultaneously along with a manatee sighting were considered 100% positive.

Table 2. Criteria used to define confidence values for each of the potential manatee photo captured with the SSS.

Score Criteria % of confidence in the photo 1 I am certain that there is no manatee in 0% the photo 2 I am not sure, but probably NOT 25% 3 I am not sure at all 50% 4 I am not sure, but probably YES 75% 5 I am certain that there is at least one 99% manatee in the photo

Aiming to compare the relative abundance of manatees between areas and months, we obtained two index of detection: GDI (Global Detection Index) and SDI (Sonar Detection Index) , expressed by the following formulas:

GDI = (FT+DS+SD)/Ebs+Efp

where FT= Number of Feeding tracks, DS= Number of direct sightings, SD=

Number of sonar detections. Ebs = Effort of boat survey in time (h), and Efp= Effort of fixed point surveys (h).

SDI= SD/Ebs

where SD= Number of sonar detections, and Ebs = Effort of boat survey in kilometers (km).

Multiple pairwise comparisons (Kruskal-Wallis test) by conducting Steel Dwass- Critchlow-Fligner procedure, was used to investigate the differences in GDI and SDI

Manatees in French Guiana 2015 between units, in order to determine a spatial tendency in the manatee abundance. Also, the same test was applied to explore the effect of temporality on the results.

A gross estimate of the minimum number of individuals (MNI), was given by the highest number of manatees detected by sonar or visually during the same day, for the same area. If evidence obtained with SSS was recorded simultaneously with a direct sighting, the manatee was considered the same, and counted as one. Feeding tracks were considered as a confirmation of presence (1 - 0), but not as an estimative of abundance. Thus, through manual analysis of the collected evidences, we calculated the minimum possible number of manatees present in each unit. We analyzed all the records collected, and according with date, hour and coordinates, decided the minimum number of manatees sighted in each unit. For example, if the same day we observed a manatee at the estuary and have another record 3 hours after, in the upper part of the same river, we considered a minimum of two manatees at this unit. If the first sighting consisted in two individuals, then the MNI was 3. To compare between units, we apply a correction factor dividing MNI by the effort in time.

Boat traffic. The permanence of the vessel, defined as the time that the vessel was observed in the area, was also recorded and multiplied by the category to obtain the disturbance of each vessel. The total BDI was defined as the sum of all the events of boat presence, divided by the sampling time by the formula: BDI= (t1C1 + t2C2 + …+ tnCn)/T, where tn is the presence time of n vessel, Cn is the category of n vessel and T is the sampling time. Additionally, we recorded all the fishing activities that were detected.

6 RESULTS

6.1 Effort

We completed 47 days of field work, and an effective sampling time of 206.13 hours (84.88% dedicated to boat surveys and 15.11% to fixed points) (Table 3 and 4). We conducted 40 silent waiting from fixed points and 126 boat-based surveys. The mean duration of boat surveys was very variable, ranking from 7 to 364min ( = 94.57, SD±79.49), while the surveys from fixed points lasted between 10 and 90min (

Manatees in French Guiana 2015

46.75, SD±20.02). In total, 922.43 km of rivers were surveyed at 5.89 km/h in average. The effort invested per unit in boat-surveys varied from 782min (70.27km) in Oyapock, to 1481min (139.37km) in Kaw.

Table 3. Distribution of field trips into the three sessions.

Unity Session 1 Session 2 Session 3 1 Coswine 29 & 30 Oct 12 & 13 Dec 21 & 22 March 2 Mana 23 & 24 Oct 9 Jan 5 & 6 March 3 Iracoubo 17 & 18 Oct 4 Jan 25 March 4 Sinnamary 16 & 23 Oct 5 Jan 24 March 5 Kourou 14 & 24 Oct 27 Nov 27 Feb 6 Cayenne 13 & 15 Oct 16 & 17 Dec 20 & 21 Feb 7 Kaw 8 & 9 Oct 19 & 20 Dec 11 & 12 March 8 Approuague 10 & 11 Oct 06 & 7 Jan 18 March 9 Oyapock 20 & 21 Oct 16 & 17 Jan 14 April

Table 4. Effort invested in each study area using two different methodological approaches: Boat-based survey using SSS and observations from fixed points.

Fixed points Boat surveys Unity Number of Effort in Number Effort in Effort in Total Effort in surveys time (min) of Surveys time (min) Distance (km) time (min) 1 Coswine 1 12 32 1435 136.7 1447 2 Mana 3 108 11 1443 114.91 1551 3 Iracoubo 6 300 7 1023 78.57 1323 4 Sinnamary 6 290 7 870 52.21 1160 5 Kourou 2 120 14 935 82.39 1055 6 Cayenne 7 320 18 1288 118.75 1608 7 Kaw 4 240 7 1241 139.37 1481 8 Approuague 6 290 7 1481 129.26 1771 9 Oyapock 5 190 8 782 70.27 972 Total 40 1870 111 10498 922.43 12368

The biggest investment in observations from a fixed point was registered in Cayenne (320min), due to the presence of several hot-spots in areas of beaches and estuaries that deserved more investment of time. The general effort was similarly

Manatees in French Guiana 2015 distributed between the three sessions; however, the effort among sessions was not equal for some of the areas(Table 5, Figure 5). Figures 6 and 7show the units and rivers surveyed

Table 5. Effort in distance and time invested in each session using two different methodological approaches: Boat-based survey using SSS and observations from fixed points.

Session Total 1 2 3 Unity Distance Time Distance Time Distance Time Distance Time (km) (min) (km) (min) (km) (min) (km) (min) 1 Coswine 46.99 478 47.04 483 42.67 486 136.7 1447 2 Mana 37.43 590 40.21 481 37.27 480 114.91 1551 3 Iracoubo 47.89 645 8.68 335 22 343 78.57 1323 4 Sinnamary 34.15 550 12.2 310 5.86 300 52.21 1160 5 Kourou 37.02 565 21.63 248 23.74 242 82.39 1055 6 Cayenne 35.12 477 42.22 472 41.41 479 118.75 1608 7 Kaw 37.3 365 35.37 508 66.7 608 139.37 1481 8 Approuague 39.5 494 44.86 724 44.9 553 129.26 1771 9 Oyapock 17.38 300 28.22 370 24.67 302 70.27 972 Total 332.78 4464 280.43 3931 309.22 3793 922.43 12368

Figure 5. Differences in effort (time and distance) between months of the survey. Note that Sessions 2 and 3 were distributed in three months.

Manatees in French Guiana 2015

Figure 6. Areas surveyed in French Guiana to evaluate the manatee population: 1. Coswine, 2. Mana, 3. Iracoubo, 4. Sinnamary, 5. Kourou, 6. Cayenne, 7. Kaw, 8. Approuague and 9. Oyapock. Map Source: NatGeo World Map 14

Manatees in French Guiana 2015

Fig. 7. Boat-based surveys (in red) and observation points (triangles) conducted to evaluate the manatee population in French Guiana. Some areas as the Oiapoque River were discarded due to inaccessibility or irrelevance for manatee surveys. Strongest lines are showing areas surveyed intensively.

Additionally, 31 interviews were completed, including 29 men and two women (Fig. 8). The interviews were developed in eight of the nine study areas. The largest number of interviews was registered in Oyapock (n=12).

Manatees in French Guiana 2015

Kourou Cayenne 4% 11%

Approuague 11% Oyapock 44%

Sinnamary 15%

Iracoubo 15%

Fig.8. Distribution of interviews developed in French Guiana during the first phase of surveys

6.2 Survey conditions

During boat transects, 1235 photos were captured using the SSS. From these, 449 were selected to describe major features of the habitat and survey conditions. The speed of the vessel was =5.71 km/h, and the sonar range was 19.6 in average. The rivers surveyed showed an average depth of 3.78m (Min=1; Max=18.44) (Table 6).

Table 6. Major aspects of survey conditions estimated using SSS captions (n= 449).

Depth (m) Speed (km/h) Unit Area N Av. Min Max SD Av. Min Max SD 1 Coswine 81 3.02 1.01 9.80 2.16 5.53 4.20 6.80 0.65 2 Mana 39 4.02 1.25 9.10 2.53 5.14 4.10 6.80 0.74 3 Iracoubo 47 3.06 1.01 9.39 2.00 6.08 4.51 6.92 0.59 4 Sinnamary 22 4.23 1.22 8.23 1.96 6.15 4.34 6.92 0.73 5 Kourou 43 5.32 1.10 8.84 2.58 5.87 4.18 7.00 0.71 6 Cayenne 66 3.80 1.07 10.43 2.37 5.54 4.00 6.92 0.88 7 Kaw 71 2.99 1.04 7.80 1.98 5.83 4.00 7.00 0.66 8 Approuague 32 4.93 1.16 18.45 3.72 5.82 4.10 6.92 0.89 9 Oyapock 48 4.43 1.04 9.80 3.02 5.78 4.10 7.00 0.78 Total 449 3.79 1.01 18.45 2.56 5.71 4.00 7.00 0.77

Manatees in French Guiana 2015

6.3 Evidences of manatee presence

Four-teen direct sightings of manatees were recorded, seven during boat surveys and seven from fixed point. Manatees were detected visually during respiratory behaviors, but the observations occurred very quickly and it was not possible to take photos. Also, 34 feeding areas were counted during boat surveys. Feeding areas consisted in patches of aquatic macrophytes as Mucu-mucu (Crinum sp.) and gramineae (Echinochloa polystachia). The vegetation showed typical signs of consumption by manatees (Fig. 10).

Figure 10. Manatee feeding tracks (Kaw River, 2012)

Following a pre-classificatory process, 91 photos obtained with the sonar were considered candidate for the blind peer-review analysis (Fig 11). Six experts accepted our invitation to score the catalog via online. All of them had experience using SSS in habitats similar to those found in French Guiana, excepting one (KAG), who has used this method mostly in shallow lagoons. The accumulated SSS experience of the reviewers totalized >12 y. After computing the results, 69.47% of the photos resulted with CV≤60% and were discarded from the analysis. Twenty-nine captions (30.52%) were considered as trusty evidences of manatee presence (CV>60%) (Fig 12 and 13). Only three SSS captions where confirmed in situ by direct sightings: one in the Kaw River, the second in the Kourouai River, a tributary of the Approuague; and the latest in Mana River. Although the rest of the photos were not confirmed by visual detection, 30.7% of the best scored SSS images (CV>60%) occurred in areas where feeding areas were observed at the same day of survey, reinforcing our suspicions of manatee presence in the area.

Manatees in French Guiana 2015

Figure 11. Process to decrease misinterpretation errors in side-scan sonar images evaluation.

Manatees in French Guiana 2015

A B M S M S

S M

C D M

Figure 12. Examples of side-scan sonar images considered positive for Antillean manatees in French Guiana. A) Kourou, 14/10/2013, CV=0.77; B) Cayenne, 15/10/2013, CV=0.79; C) Sinnamary, 16/10/2013, CV=0.67; D) Oyapock, 20/10/2013, CV=0.69. M=Manatee, S= Shadow.

Manatees in French Guiana 2015

A B

C D

Figure 13. Examples of side-scan sonar images considered positive for Antillean manatees in French Guiana (Cont.). A) Kourou, 27/11/2014, CV=0.80; B) Oyapock, 16/01/2014, CV=0.70; C) Sinnamary, 14/04/2014, CV=0.81; D) Oyapock, 14/04/2014, CV=0.90.

Manatees in French Guiana 2015

Summarizing, 78 evidences of manatee presence were recorded: 29 SSS selected manatee captions, 14 direct sightings and 35 feeding tracks (Table 7, Fig 14). The calculated detection index (GDI) was 0.39 evidences per hour of survey. All the manatees detected visually were apparently solitary, and none calf was sighted. However, at least two SSS image showed the presence of two or maybe three manatees (in Kourou and Ouanari-Oyapock, respectively), but it was not possible to establish the size of the animals. Manatees were confirmed visually in all the units, except Cayenne and Oyapock.

Table 7. Evidences of manatee presence recorded in nine units in French Guiana. GDI: Global Detection Index, number of evidences per hour of survey.

Unit Area Direct Feeding Sonar Total Effort GDI sighting track detection (hr) (CV>60%) 1 Coswine 2 8 7 17 24.12 0.70 2 Mana 3 6 2 11 25.85 0.43 3 Iracoubo 2 2 3 7 22.05 0.32 4 Sinnamary 1 --- 1 2 19.33 0.10 5 Kourou 1 2 5 8 17.58 0.45 6 Cayenne ------3 3 26.80 0.11 7 Kaw 3 3 2 8 24.68 0.32 8 Approuage 2 6 1 9 29.52 0.30 9 Oyapock --- 8 5 13 16.2 0.80 Total 14 35 29 78

Manatees in French Guiana 2015

Direct sightings Sonar detection Feeding tracks

Figure 14. Manatee distribution areas. Direct sightings are represented by red, sonar detection by blue and feeding tracks by green. The transects are represented in yellow. Units 1 (Coswine) and 2 (Mana)

Manatees in French Guiana 2015

Direct sightings are represented by red, sonar detection by blue and feeding tracks by green. The transects are represented in yellow. Unit 3 (Iracoubo)

Manatees in French Guiana 2015

Direct sightings are represented by red, sonar detection by blue and feeding tracks by green. The transects are represented in yellow. Units 4 (Sinnamary) and 5 (Kourou).

Manatees in French Guiana 2015

Direct sightings are represented by red, sonar detection by blue and feeding tracks by green. The transects are represented in yellow. Units 6 (Cayenne) and 7 (Kaw)

Manatees in French Guiana 2015

Direct sightings are represented by red, sonar detection by blue and feeding tracks by green. The transects are represented in yellow. Units 8 (Approuague) and 9 (Oyapock)

Manatees in French Guiana 2015

Manatee evidences were found in all the units, with the highest detection index in Oyapock (0.80 ev/hr) and Coswine (0.70 ev/hr) (Fig 15).

Direct sighting Feeding track Sonar detection

18 16 14 12 10 8 6 4 2 0

Direct sighting/hr Feeding track/km Sonar detection/km

0.25

0.2

0.15

0.1

0.05

Figure 15. Absolut (superior) and relative (inferior) abundance of manatee evidences recorded in nine units in French Guiana, during boat-surveys and observations from fixed points.

The indexes of detection (GDI and SDI) showed a better relation evidences/effort in surveys conducted at Oyapock, Coswine and Kourou (Fig. 16). Both GDI and SDI were significant different between units (GDI: Kruskal-Wallis 9.897, p=0.272, df=8; SDI: Kruskal-Wallis 11.124, p=0.195, df=8)

Manatees in French Guiana 2015

2.8

2.3

1.8

GDI 1.3

0.8

0.3

-0.2

0.12

0.1

0.08

0.06

SDI 0.04

0.02

-0.02

Figure 16. Comparison of manatee detection (Global Detection Index, GDI and Sonar Detection Index (SDI) between units. The point is the average index in three sessions, and the bars indicate Standard Deviation (SD). Note the large SD for SDI analyses in almost all units.

Manatees in French Guiana 2015

As the figure 16 shows, the SD for SDI values is very large in almost all units, excepting for Cayenne. This indicates a high inter-session variation. The statistical analysis showed that GDI and SDI are significantly different between sessions (GDI: Kruskal-Wallis 2.956, p=0.228, df=2; SDI: Kruskal-Wallis 7.27, p=0.026, df=2). The Dwass-steel-Chritchlow-Fligner test for all pairwise comparisons showed differences between sessions 1 and 2, and 1 and 3 but not between 2 and 3 (Fig. 17).

Direct sighting Feeding track Sonar detection

0 Session 1 Session 2 Session 3

0.15 2.0

1.5 0.10

1.0

SDI GDI

0.05 0.5

0.00 0.0 1 2 3 1 2 3 Session Session

Figure 17. Absolut (superior) and relative (inferior) abundance of manatee evidences (Indexes) recorded in French Guiana, during three survey sessions.

The survey was conducted during seven months, with the biggest effort per month occurring in October, which was also the month when more evidences of manatee presence were collected. However, April was the month with higher index of manatee evidences, consisted only in feeding tracks. Interestingly, the GDI had a temporal

Manatees in French Guiana 2015 pattern (between months) opposite to SDI (Fig. 18). This may be due to the fact that feeding tracks are taking into the account to calculate the GDI. During March and April, the absolute and relative frequency of feeding tracks was higher. The SDI considers only detections by SSS, which were more frequent during the month of October.

Evidences Effort (hr) GDI (ev/hr)

90 1.8 80 1.6 70 1.4 60 1.2

50 1

40 0.8 GDI 30 0.6 20 0.4 10 0.2 0 0 October November December January February March April

Sonar detection Effort (km) SDI (ev/km)

350 0.06

300 0.05

250 0.04

200

0.03 SDI 150 0.02 100

50 0.01

0 0 October November December January February March April

Figure 18. Differences of Global Detection Index (GDI) and Sonar Detection Index (SDI) between survey months.

According to the analysis of manatee evidences, and assuming that the possibilities or manatees crossing between units is low, a minimum of 23 manatees

Manatees in French Guiana 2015 inhabit the rivers of French Guiana (Fig. 19). We confirmed the presence of manatees in every unit of the study area, but after analysis, the number of potentially different manatees was apparently bigger in Kourou (MNI=5), followed by Iracoubo (MNI=4), and Oyapock and Coswine (MNI=3).

MNI/hr GDI (Ev/hr)

0.3 0.9 0.8 0.25 0.7

0.2 0.6

0.5 0.15 0.4 GDI MNIhr / 0.1 0.3 0.2 0.05 0.1 0 0

Number of evidences Minimum Number of Manatees

18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0

Fig. 19. Superior: Evidences of manatee presence (SSS captions + direct sightings + feeding tracks) obtained for each unit of French Guiana; and estimated Minimum Number of Individuals (MNI). Inferior: relative index of abundance and relative MNI.

Manatees in French Guiana 2015

6.5. Conservation state The persons interviewed during the research (N=31) were French (48.3%), Brazilian (38.7%), Guianese (6.45%) or unknown (6.45%). Three of the interviewers were women, and the ages ranged between 30 and 80 years old. All the interviewers have seen manatees in the area except one Guyanese fisherman who fishes mainly in open waters; and a French housewife, with few contact with manatee habitats. The interviewers claimed that manatees are present in the shallow part of the rivers, or in small creeks and calm rivers. They also said that manatees are relatively easy to observe in the estuaries. At least seven persons had seen manatees around the time of the interview (the day before, the week before, or few weeks ago). Some of the interviewers gave information of areas were manatees can be found (Fig. 21).

As about potential or actual threats on the species, most of the interviewers believe that manatees have not serious threats in French Guiana. However, we also compiled the following information:

- Entanglement in fishing nets or incidental capture: One man in Approuague commented that manatees are eventually trapped in fishing nets, but they are normally released before they die. If a manatee is found dead in the net, people use to eat it. Another fisherman in Iracoubou has heard about manatee entanglement, but commented that it has never happened to him. A fisherman in the Ouanary community related that ten years ago two manatees got entangled in his fishing net. He managed to release one of the animals, but the second one died and was used for human consumption. In Cayenne, another fisherman captured a manatee in a shrimp net in 2011, but released it alive. A Brazilian fishermen explained that back in the years the use of ¨rede cortinera¨ (a special type of fishing net) was still allowed, and manatees got easily trapped in it. Currently, this kind of fisheries is forbidden and incidental capture of manatees in fishing nets is apparently uncommon. - Hunting or intentional capture. In Ouanary (Oyapock), the eldest men of the community related that hunting was a common practice back in the 80’s; but after the creation of laws to protect natural areas in French territory, this activity is no longer practiced. Also, the few experienced manatee hunters living in Ouanary already passed away. A man from the Tampack community (Oyapock) told us that

Manatees in French Guiana 2015

three years ago some people intentionally captured manatees in Regina (Approuague) using fishing nets. Another fisherman commented that manatee hunting still happens at the Brazilian side of the Oyapock River, by poaching or using fishing nets. A man from Ouanary told us that manatees are killed in Brazil in order to collect the ear bones. The reasons of why this is happening are not clear. - Boat collisions: Although several interviewers claimed that this is not an actual cause of dead for manatees in French Guiana, we received two reports of recent boat collisions. One fisherman from Iracoubo declared that he may have struck himself a manatee with his boat in Counnamama one month before the interview. He didn’t attend the animal or inform the authorities. He couldn’t say if the animal was wounded or dead. Another case of boat collision was informed by a person from Coswine: a manatee was collided by a boat in the estuary of Kaw River.

Boat traffic was verified only during six surveys, in five out of nine areas. We recorded 15 vessels: Six in Cayenne (Mahury River), two in Sinnamary River, two in Kaw River, three in Kourou and two in Mana (Table 8). However, the necessary information to calculate the BDI was collected only in four cases. The estimated BDI varied from 0.11 (Kaw) to 2.43 (Kourou). In all cases, the vessels were large in size and power; and remained between 2 and 34 min at the visual area ( = 6.8 min). Due to the number of vessels and BDI, the areas presenting the biggest and potentially dangerous boat traffic level were Cayenne and Kourou.

Manatees in French Guiana 2015

Figure 19. Localities reported by interviewers as important areas for manatees (Trichechus manatus) in French Guiana and Amapa State (Brazil).

Manatees in French Guiana 2015

Table 8. Boat traffic recorded during the manatee boat-based surveys in French Guiana. BDI= Boat Disturbance Index

Date River Sampling # vessel Hour Presence Engine BDI Total BDI time time category 09-oct Kaw 144 1 09:20 5 2 10 0.111111111 2 10:34 2 3 6 13-oct Mahury, Cayenne 118 3 10:11 3 3 9 0.316666667 4 10:23 2 2 4 5 10:30 3 2 6 14-oct Kourou 60 6 09:30 2 3 6 2.433333333 7 09:47 34 4 136 8 10:06 2 2 4 16-oct Sinnamary 60 9 11:48 12 4 48 0.95 10 12:00 3 3 9 16-dic Mahury, Cayenne 11 10:47 12 10:48 13 11:31 09-ene Mana 14 Acarouani, Mana 15

Manatees in French Guiana 2015

7 DISCUSSION

7.1 Methodological constrains During the boat surveys, we only detected manatees visually in 14 opportunities, but captured at least 29 photos with the SSS with good chances of being positive for manatee, according to the opinion of a group of experts. Both sightings and manatee detections with the sonar were confirmed in most of the times by the observation of typical feeding tracks of manatees at the same area. However, this methodology is still far to produce ideal results in order to assess manatee abundance, due to:

1) Uncertainty and variability of detection rates using SSS. The main limiting factor of the SSS is the unknown detection rate (Gonzalez-Socoloske and Olivera- Gomez 2012). The SSS detection ability in field can be affected by weather, boat speed, depth, current speed and direction, type of environment and observer experience/fatigue. For instance, our data showed a high relative number of evidences in Coswine, but perhaps the detection ability of the sonar was better at this area due to the habitat type. In some areas, the bottom was muddy and flat, with few objects present (debris, plants, rocks, etc). In others, like Ouanary River at the Oyapock unit, the bottom presented an important amount of rounded rocks that could be easily mistaken as manatees. At least eight field biologists, with a variety of experience and skills levels, participated in the boat surveys and in the manipulation of the side-scan sonar. Finally, the data was collected in a lapse of seven months, with no quantified variations in general hydro-climatic conditions. Since most of these factors are still unknown or poorly understood, then it is impossible to correct the error caused by detectability conditions in field.

2) Subjectivity during the process of recognizing manatees in SSS images. Following a precautionary principle, we tried to avoid or to reduce the overestimation in manatee numbers. Therefore, we attempted to establish a scoring procedure during which the confidentiality of each image was quantified, allowing us to discard ‘bad’ rated photos accordingly. However, our method is still subjective and limited by a number of human factors. First, we counted with a reduced number of participants, and therefore few accumulative years of experience. That is due to several reasons, but mainly because, at global level, there are still few experts in this area. Secondly, the

Manatees in French Guiana 2015 variability of detection ability of each participant is unknown and somehow unmeasurable. It could be affected by the habitat and conditions that the researcher is familiar with, years of experience, and personal skills. Once again, since this variability is impossible to assess, no correcting method could be applied to the peer-review process.

7.2 Spatial variation The indexes of detection (GDI and SDI) showed a better relation evidences/effort in surveys conducted at Oyapock, Coswine and Kourou; which may suggest a denser population of manatees. However, the obtained information is not sufficient to infer if the differences in GDI and SDI are due to manatee abundance itself or to factors affecting manatee detection (see methodological constraints). In despite of being a challenging area in terms of logistic, Oyapock was the unit with better results in number of evidences per effort. This is noticeable for example during the month of April, when eight feeding areas where recorded in Oyapock unit after only five hours of effort. At least three different manatees were detected in this area. Coswine was another important area (MNI=3). Both Coswine and Oyapock are located at the political borders of French Guiana (with Surinam and Brazil respectively).

7.3 Temporal variation The analysis of temporal variation using indexes showed that manatees are apparently more detectable visually and with the SSS during the months of October, November and December, while sightings decrease during the first months of the year. However, detections of feeding tracks are more frequent during the peak of the rainy season. Precipitation seems to increase dramatically in December and continue augmenting in the first part of the year (Marchand et al. 2004), with the consequent rising in the water level. Therefore, after December, manatees may have more habitats to ‘escape’ from the visual area of the observers, and from the caption area of the SSS. In some places, the forest gets flooded, providing a perfect habitat for hiding. These hydro-climatic conditions may explain the difficulty of obtaining direct sightings and sonar images during the rainy season (January – April). This variation in habitat use and feeding behavior has been reported for other fluvial systems where manatees inhabit, such as Orinoco (Castelblanco-Martínez et al. 2009) and Amazon Basins (Arraut et al. 2009).

Manatees in French Guiana 2015

7.4 Abundance, distribution and conservation The proposed methodological approach aimed to have an intense and coordinate field effort during a short period of time in order to avoid over counting of animals. However, due to a number of logistical factors, this design was not rigorously applied. Nevertheless, it was still possible to get a gross estimate of the minimum number of individuals (MNI), given by the highest number of manatees detected by sonar or visually during the same day, for the same area. According to this simplistic analysis, at least 23 manatees inhabit the rivers of French Guiana. Manatees are very elusive animals and the detection rate obtained by boat surveys (even using the SSS) is unknown but presumably low. Manatees may be easily disturbed by the noise of the engine and flee rapidly from the caption area of the SSS. Most of the rivers present constant meandric curves, decreasing the visual area of the observers. These factors affecting manatee detection probably become even more decisive during the rainy season. For these reasons, it is reasonable to consider that the number of manatees in French Guiana may be much higher that the obtained MNI, although continue to be unknown. The fact that the three types of evidences were obtained in all the rivers, gives an optimistic idea of the population situation, which seems to be widely spread across the territory. Additionally, the interviews demonstrated that encounters with manatees are relatively common (in comparison with other areas of the species distribution), supporting the idea of a well conserved and relatively abundant population of manatees. All the localities in French Guiana reported by interviewers as important areas for manatees were confirmed in field by direct sightings or sonar images.

Manatee mortality due to entanglement or to intentional hunting seems to be low, although awareness on the species needs to be reinforced. However, collision with boats may be an increasing risk on manatees, especially in areas with denser human population as Cayenne, and frequented areas by fishermen as the estuaries. Other threats on manatees such as contamination caused by gold mining activities need to be investigated. Previous studies showed the human population from French Guiana to have high exposure to mercury at levels exceeding WHO recommendations (Fréry et al. 2001). Levels of mercury, evaluated through measurements in hair and food, are related to high consumption of fish, which is not the case for an herbivorous species as the manatee. Also, it has been shown that areas close to estuaries (those used more often by manatees) present very low Hg concentration, while the upper part of the rivers are the

Manatees in French Guiana 2015 most drastically affected (Laperche et al. 2014). However, the consequences of any level of contaminants in manatees are still poor understood and deserve further consideration.

8 CONCLUSIONS

Assessing manatee abundance and distribution turbid waters is one of the main obstacles to evaluate the conservation state of the species in the continent. To our knowledge, this is a pioneer attempt to assessing manatee abundance in a vast territory of South America by using boat-based surveys and SSS.

 The results of both boat-based surveys and interviews confirmed the presence of manatees in all the rivers and estuaries of French Guiana. The areas that are presumably more important for manatees are Oyapock (Ouanary River), Kourou and Coswine.  It was not possible to assess the actual number of manatees at the territory, but the results indicate a minimum population size of 23 manatees. The presence of calves was not confirmed.  No evident threat on manatees was detected during the boat-based surveys, with few boat traffic recorded. Based on information collected from interviews, potential threats on manatees are: Boat collisions, entanglement in fishing net, and in less degree, hunting. The proximity with other regions (Suriname and Brazil), with potential conservation issues, may be a source of risks for the local population of manatees.

9 RECOMMENDATIONS  Surveys conducted in the units Coswine (frontier with Suriname) and Oyapock (frontier with Brazil) happened to produce high numbers of evidences, and the biggest estimated MNI. Since the conservation status of manatees in Surinam and Amapá State (Brazil) are poorly known, these areas deserve special attention for further management plans, as well as binational efforts to coordinate actions for its preservation.  I recommend developing annual surveys following the same methods, in order to monitor population changes in abundance, distribution and population structure

Manatees in French Guiana 2015

(e.g. proportion of adults/calves). While the SSS is a very helpful method, direct observations should continue to be an important complement of surveys. If possible, simultaneous surveys would be informative as proposed initially.  It is recommendable that further censuses using boat-base surveys will be conducted only during a short period of time, ideally dry season, to maximize the detection capability of the methods and to avoid the bias caused by temporal variations, Also, each unit should be survey under the same schedule conditions to facilitate the spatial analysis. If possible, it should be considered to survey 2 or more areas simultaneously to guarantee a low level of re-counting.  More information on health status, genetic structure and movement of manatees in French Guiana is necessary to have a clear picture on the population status; and therefore, to propose adequate management plans for the species. The present report offers key information on the most important areas for manatees, as well as some ecologic characteristics of the habitats. Those elements are necessary to coordinate future capture procedures in order to sample and tag manatees.  Boat collisions seem to be a potential and increasing problem for manatees, especially in locations near cities. Manatee awareness campaigns may be necessary in areas with increasing boat traffic. After collecting more information on this regard, perhaps would be interesting to discuss some conservation strategies like boat speed regulation.  Likewise, interaction with the local community is a key tool to increase our limited knowledge on manatees in French Guiana. More information collected by properly done interviews would be very informative.

10 ACKNOWLEDGEMENTS

This study was funded by the Parc National de La Guadeloupe, the French Direction de l’Environnement, de l’Aménagement et du Logement de Guyane (DEAL Guyane) , the Office National de la Chasse et de la Faune Sauvage and the CAR- SPAW. The logistic arrangements were provided by the NGO Kwata. Credits are due to the Director of Kwata, Benoit de Thoisy, for the coordination of field activities, participation in the surveys and comments on the manuscript. Thanks to the field biologists of Kwata, Virginie dos Reis and Sébastien Barrioz, who conducted an

Manatees in French Guiana 2015 important part of the surveys. I also thank Sebastien Rives, Régis Gomes and Boris Leresbours from the Parc National de La Guadeloupe, for their collaboration during the first phase of data collection. Thanks to John Reynolds, Benjamin Morales Vela, Thomas O’Shea and Alejandro Acosta for the comments and recommendations on the analysis and first version of the report. I specially thank Hector Hernández Arana for helpful advices on data analysis and sampling design.

LITERATURE CITED

Arraut EM, Marmontel M, Mantovani JE, Novo EMLM, Macdonald DW, Kenward RE. 2009. The lesser of two evils: seasonal migrations of Amazonian manatees in the Western Amazon. Journal of Zoology (London) 280: 247-256. Artigas LF, Vendeville P, Leopold M, Guiral D, Ternon J-F. 2003. Marine biodiversity in French Guiana: estuarine, coastal, and shelf ecosystems under the influence of Amazonian waters. Gayana (Concepc.) 67: 302-326. Castelblanco-Martínez DN. 2004. Peixe boi Trichechus manatus manatus na Orinoquia Colombiana: Status de conservação e uso de habitat na época seca. [MSc Thesis]. [Manaus, Brasil]: Instituto Nacional de Pesquisas da Amazônia/INPA. Castelblanco-Martínez DN. 2012a. Ecology, genetics and conservation of manatees in French Guyana, Park de la Guadaleoupe. Castelblanco-Martínez DN. 2012b. Relative abundance and conservation status of manatees (Trichechus manatus manatus) in French Guyana --- Preliminary analysis of the study area, Park National de La Guadeloupe, France. Castelblanco-Martínez DN, Bermúdez-Romero AL, Gómez-Camelo IV, Rosas FCW, Trujillo F, Zerda-Ordoñez E. 2009. Seasonality of habitat use, mortality and reproduction of the Vulnerable Antillean manatee Trichechus manatus manatus in the Orinoco River, Colombia: implications for conservation. Oryx 43: 235-242. Castelblanco-Martínez DN, de Thoisy B. 2012. Rapid evaluation of methods to monitoring manatees Trichechus manatus manatus in French Guyana. In: 15ª Reunión de Trabajo de Expertos en Mamíferos Acuáticos de América del Sur (RT 15ª) y 9º Congreso de la Sociedad Latinoamericana de Especialistas en Mamíferos Acuáticos, Puerto Madryn, Argentina de Thoisy B, Spiegelberger T, Rousseau S, Talvy G, Vogel I, Vie JC. 2003. Distribution, habitat, and conservation status of the West Indian manatee Trichechus manatus in French Guiana. Oryx 37: 431-436. Dedieu N, Allard L, Vigouroux R, Brosse S, Céréghino R. 2014. Physical habitat and water chemistry changes induced by logging and gold mining in French Guiana streams. Knowledge and Management of Aquatic Ecosystems: 02. Fréry N, Maury-Brachet R, Maillot E, Deheeger M, De Merona B, Boudou A. 2001. Gold-mining activities and mercury contamination of native amerindian communities in French Guiana: key role of fish in dietary uptake. Environmental Health Perspectives 109: 449. Gonzalez-Socoloske D, Olivera-Gomez LD. 2012. Gentle Giants in Dark Waters: Using Side-Scan Sonar for Manatee. The Open Remote Sensing Journal 5: 1-14.

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Laperche V, Hellal J, Maury-Brachet R, Joseph B, Laporte P, Breeze D, Blanchard F. 2014. Regional distribution of mercury in sediments of the main rivers of French Guiana (Amazonian basin). SpringerPlus 3: 1-11. Marchand C, Baltzer F, Lallier-Vergès E, Albéric P. 2004. Pore-water chemistry in mangrove sediments: relationship with species composition and developmental stages (French Guiana). Marine Geology 208: 361-381. Self-Sullivan C, Mignucci-Giannoni A. 2008. Trichechus manatus ssp. manatus. IUCN 2011. IUCN Red List of Threatened Species. Version 2011.2. <¡Error! Referencia de hipervínculo no válida.. Downloaded on 22 May 2012. Accessed Date Accessed.| doi:DOI| Spiegelberger T. 2002. Analysis of a habitat used by Antillean manatee (Trichechus manatus manatus) in French Guiana: Technische Universität München. Spiegelberger T, Ganslosser U. 2005. Habitat analysis and exclusive bank feeding of the Antillean manatee (Trichechus manatus manatus L. 1758) in the Coswine Swamps of French Guiana, South America. Tropical Zoology 18: 1-12.

Manatees in French Guiana 2015

APPENDIX I. Interview Form

General data Code: Interviewer: Locality: Observations: Date:

General data of the interviewee Name: Origen place: Age: Time living at the area: Living place: Ocupation Areas more visited

Part 1: Knowledge of the species Do you know what is a Have you ever seen a manatee?: Yes  Not manatee: YES  No Describe a manatee (color, size, behavior, habitat)

Part 2: Distribution areas and habitat use There are manatees in French Guiana? Yes  No

If the answer is YES,¿What are Beaches  Rivers Channels  Estuaries the hábitats for manatees? NS/NR

Others  Specify:

Define the sighting frequency for each area [*common: Once a month, Rare: Once a semester, very rare : Once a year; Absent: Never; NK/NR: The interviewee does not know, or does not want to answer]

Subarea Common Rare Very Rare Absent NK/NR 1) Coswine 2) Mana 3) Iracoubo 4) Sinnamary 5) Kourou 6) Cayenne 7) Kaw 8) Approuague 9) Oyapock

Manatees in French Guiana 2015

Part 3: Seasonality of sightings ¿When do manatee sightings Rainy season Dry season No seasonality  are more frequent? NS/NR

¿When is the reproductive Rainy season Dry season No seasonality  season? NS/NR

¿What time of the day is more Morning  Evening Night  Anytime  easy to see them? NS/NR

Part 4: Sightings and evidences ¿Have you seen manatees in FG? yes  No

If the answer is afirmative, give details of the encounters Date Place1 Type of Age/size Time Encounter Observations evidence2 duration

1According to the areas 2 Sighting , feeding areas, carcasse, fezes

Part 5: Ecology 1. Diet items: ______2. Have you observed feeding behaviors? Describe: ______3. Predators? : ______

Manatees in French Guiana 2015

Parte 6: Conservation 1. Have you seen a dead manatee? Detail (place, date, cause of date, destination of the carcasse) ______2. Main threats? Boating  Fishing  Entanglenment  Water pollution  Habitat loss  Hunting/Poaching  Other  Specify ______3. In comparison to the past years, manatees are More frequent less frequent same NS/NR 4. Are manatees important for the area? Yes  No Why? ______

¡Thanks!

Manatees in French Guiana 2015

APPENDIX II. Online survey

Manatees in French Guiana 2015