integrating fads monitoring with co-management structures – a … · 2017-07-11 · integrating...

Integrating FADs monitoring with co-management structures – A pilot study Kennedy Osuka, Michael Murunga, Melita Samoilys and Clay Obota

July 2016

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Acknowledgement CORDIO East Africa would like to thank Yann Yvergniaux, Dominique Greboval and Patrick

Kimani of the Indian Ocean Commission-‐SmartFish for their support in implementing Fish

Aggregating Devices (FADs) catch monitoring component. Sincere thanks to the EU who are

funding the IOC-‐SmartFish Programme for funding this component in advancing FADs fishing in

Kenya.

Many thanks to our data collectors Sadiki Hassan Tondwe, Shida Hamadi Mwajambia, Tashrifa

Hassan Said, Bibi Bakari Nyuni, Majaliwa Salim Mwarora, Bakari Mohamed Mchinga, Fatuma

Hamisis Mshenga, Hatibu Ali Omar and Mwanahawa Bakari Chirumu for their tireless effort to

consistently collect data over the eight months of FADs catch monitoring. Our special thanks to

fishermen from Gazi, Mwandamo, Mkunguni, Mwaembe and Munje Beach Management Units

(BMUs) where the FADs catch monitoring program was done for taking part in catch monitoring

and honestly answering the questions from our data collectors.

We are indebted to all the FADs development steering group members composed of Patrick

Kimani (SmartFish); Elizabeth Mueni and Wanyoike Karungo (State Department of Fisheries and

Blue Economy -‐ SDF & BE); Nina Wambiji, Fatuma Mzingirwa and Pascal Thoya (Kenya Marine

Fisheries and Research Institute -‐ KMFRI): Nyaga Kanyange and Saidi Majani (Coastal and

Marine Resources Development -‐ COMRED); Isiaka Mwinyi (Mwandamo BMU); Hasani Saidi

(Munje BMU); Bakari Ndaro (Mkunguni BMU); Ali Mwabori (Mwaembe BMU) and Mohammed

Massod (Gazi BMU) for their support and critique of this document during the steering group

meetings. We also thank James Mbugua for providing assistance in processing the products of

participatory mapping.

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Table of contents Acknowledgement .......................................................................................................................... i

Table of contents ........................................................................................................................... ii

List of Acronyms ............................................................................................................................ iii

Executive summary ....................................................................................................................... iv

Introduction ................................................................................................................................... 1

Materials and methods .................................................................................................................. 3

Study sites .................................................................................................................................. 3

FAD deployment ......................................................................................................................... 3

Selection of data collectors ........................................................................................................ 4

Training of data collectors .......................................................................................................... 5

Sampling strategy ....................................................................................................................... 6

Prioritized FADs associated species ............................................................................................ 6

Participatory mapping ................................................................................................................ 7

Data analysis ............................................................................................................................... 7

Results ............................................................................................................................................ 8

Summary of sampling effort ....................................................................................................... 8

Fishing duration .......................................................................................................................... 9

Catch per unit effort (CPUE) ..................................................................................................... 10

Income ...................................................................................................................................... 11

Fork length, weights and relative abundance pelagic associated species ................................ 12

Frequency of visits to FADs ...................................................................................................... 15

Fishing zones around the FADs ................................................................................................. 16

Discussion ..................................................................................................................................... 17

Conclusion and lessons learnt ...................................................................................................... 19

References ................................................................................................................................... 21

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List of Acronyms BMU Beach Management Unit

CORDIO Coastal Oceans Research and Development in the Indian Ocean

COMRED ` Coastal and Marine Resources Development

CPUE Catch per Unit Effort

FAD Fish Aggregating Devices

IOC Indian Ocean Commission

KCDP Kenya Coastal Development Project

SDF-‐BE State Department of Fisheries and Blue Economy

MCS Monitoring, Control and Surveillance

NGO Non-‐Governmental Organization

KMFRI Kenya Marine Fisheries and Research Institute

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Executive summary

Fish Aggregating Devices (FADs) are free floating or anchored structures fabricated and setup to

attract fish. FADs promote and encourage offshore fishing or fishing just outside the reef area

particularly among local communities to capture larger and less fished pelagic species. In an

effort to evaluate the importance of FADs in improving the food security and reducing pressure

on fragile overfished coral reef ecosystems, CORDIO conducted catch monitoring of the

technology with an aim to understand the benefits of FADs in increasing access to offshore

pelagic fish. The monitoring had three components which include: conducting FAD catch data

collection training for selected BMU members, initiating FADs monitoring and data collection,

and analysing FADs catch monitoring data and reporting results. This was done at five landing

sites in Gazi, Mkunguni, Munje, Mwaembe, and Mwandamu during three deployment phases

from October 2015 to May 2016 notably Pre-‐deployment (October – November), Colonization

(December – January) and Post deployment (February – May). The impacts of FADs were

assessed by analyzing catch, effort and biological variables to derive information on frequency

of visits to FADs, changes in fishing duration, CPUE and income over the three deployment

phases. Catch records on hand lines were more relevant in assessing the catch trends since the

gear was continuously monitored throughout the three deployment phases. Results showed

that fishing duration of fishers using hand line decreased in all landing sites over the monitoring

period. Estimates on CPUE and income, which are a reflection of the fishery contribution

towards the livelihood of the fishing communities, indicated an increase after deployment of

FADs. There was also an increase in the frequency of visits to fishing grounds near FADs, which

indicated that fishermen were keen to fish around FADs. The utilization of FADs suggests that

awareness on FADs fishery was effective in increasing the visitation rates to FADs fishing

grounds. The intensity of fishing decreased during the Post-‐FAD suggesting access to FADs was

limited by the seasonal changes, access to fishing vessels and type of fishing gear. While the

FADs project in Kenya aimed to optimize benefits flowing from offshore fishing through

increased catches, caution should be taken in promoting fishing of already overexploited and

vulnerable pelagic species such as sharks, Yellowfin tuna (Thunnus albacares), which is 94%

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overexploited, Striped marlin (Tetrapturus audax), which 60% overexploited, and Narrow-‐

barred Spanish mackerel (Scomberomorus commerson). Measures such as species restrictions

are therefore recommended.

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Introduction

Kenya’s coastal fishery is predominantly artisanal (Mclanahan and Mangi 2004; Samoilys et al.,

2011a, b), supporting an estimated 13,000 fishers, increasing at 15% annually along the 640 km

coastline (SDF, 2012). The fishery is characterized as being multi-‐species and multi-‐gear making

its management difficult. The use of destructive fishing gears such as beach seines in the near

shore coral reef areas, coupled by the increase in the number of fishers joining artisanal fishery,

are some of the main causes of declining catches, which threatens the sustainability of the

fishery (Obura 2001; Fondo, 2004; Samoilys et al. 2011a). Moreover traditional gears have

dominated Kenya’s artisanal fisheries since the 1960s due to factors such as traditional believes

of inheritance and maintenance costs (Samoilys et al., 2011b; Mbaru, 2012). Development of

the fishery is impeded by the long-‐standing use of traditional fishing gears, exacerbated by high

poverty levels, inadequate capacity and few resources within the government and fishing

communities.

Fish Aggregating Devices (FADs) are free floating or anchored structures fabricated and setup

by fishers to attract fish. FADs have been widely used in the Pacific and in certain island

countries in the western Indian Ocean (WIO) such as Comoros (Désurmont and Chapman, 2000;

Bell et al., 2015). These devices promote and encourage offshore fishing or fishing just outside

the reef area particularly among local communities to capture larger and less fished pelagic

species. Since Kenya’s fishery is largely small-‐scale and artisanal, use of low-‐cost and low-‐tech

artisanal FADs is expected to improve the socioeconomic conditions of small-‐scale fishing

communities by improving their catch rates as well as alleviating pressure on overexploited

near shore resources. The use of FADs therefore presents a practical tool for increasing access

to offshore pelagic fish (Bell et al., 2015), to help feed the ever-‐increasing population along the

Kenyan coast. Considerable planning and piloting including monitoring of the technology, catch

and research is therefore needed to understand the benefits of anchored FADs in Kenya. This

would enable evaluation of the importance of FADs as an initiative in improving the food

security and reducing pressure on fragile overfished coral reef ecosystems.

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FADs fishery was first developed in Kenya in 2012 under South West Indian Ocean Fisheries

Project (SWIOFP) initiative (Mbaru, 2015). Four FADs including 2 shallow (>50m) and 2 deep

(>250m) were constructed and deployed between Mtwapa and Watamu areas. Between 2014

and 2015 KMFRI deployed other FADs in Msambweni area with funding from National

Commission for Science Technology and Innovation (NACOSTI). The two deployment efforts did

not show success due to vandalism and inadequate community sensitization and awareness.

Vandalism occurred especially in Kilifi owing to misunderstanding by the fishers about the

project (Mbaru, 2015). There exist opportunities to subvert the failures of these attempts

including the use of co-‐management structures to conduct sensitization and awareness and

collaboration in FADs development and deployment activities in Kenya.

Kenya’s State Department of Fisheries and Blue Economy (SDF-‐BE) has promoted community-‐

based management of fisheries resources through a co-‐management structure called the Beach

Management Unit (BMU), which is enshrined in the BMU Regulations of 2007 under the

Fisheries Act. The BMU structures have significantly enhanced the ability of fishers and coastal

communities to engage in fisheries co-‐management. They offer an ideal platform for

conducting trainings to impart knowledge on fisheries related issues as well as sensitization and

awareness. For instance the BMUs members in Msambweni received training on data collection

and fisheries management during a 5-‐day in residence training course funded through

SmartFish initiative (Samoilys, 2012). The full realization of BMU functions has however been

halted by the reluctance of fishers to join the BMUs. Despite this, BMUs are still a viable

platform to engage the fishing community in adopting a new technology and to participate in

monitoring, control and surveillance (MCS) of their fisheries particularly catch monitoring

(Obura, 2001).

Fish catch monitoring is critical as it provides the baseline information for measuring the impact

of an intervention. In this FADs catch monitoring project, BMU members were involved in catch

monitoring before and after deployment of FADs. The overall goal of FADs project was to

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optimize benefits flowing from offshore fishing in Msambweni area through increased catches

generated by appropriate co-‐management of four FADs in four selected sites. The specific

objectives of catch monitoring component were to:

a) Conduct FAD catch data training for selected BMU members.

b) Initiate FAD monitoring and data collection.

c) Analyse FAD catch monitoring data and report the results.

Materials and methods

Study sites

Msambweni is a sub-‐county located in Kwale County, south coast of Kenya. Fishing is the main

source of livelihood among the coastal communities in the area and accounts for >75% of

livelihood activities (Maina et al., 2013). Catch monitoring was carried out at five landing sites in

Msambweni spanning 13 km with northern-‐most landing site being located in Kinondo Ward

and the other four in Ramisi Ward. The landing sites included Gazi (lat. -‐03.5333, long.

39.6833); Mwandamo (lat. -‐04.4525, long. 39.4975); Mkunguni (lat. -‐04.47325, long. 39.4909);

Mwaembe (lat. -‐04.4725, long. 39.4915) and Munje (lat. -‐04.5004, long. 39.4726) (Figure 1).

These landing sites have a total of 858 registered fishers with Gazi and Mkunguni having the

largest proportion at 29.14% and 21.33% respectively. Mwaembe, Mwandamo and Munje have

the least number of fishers at 18.64%, 16.32% and 14.47% correspondingly. A variety of gears

are deployed in the fishing grounds overlooking the landing sites and range from traditional

gears e.g. basket traps and handlines; modified traditional e.g. speargun and gillnets; and

introduced e.g. monofilament, gillnets, long lines and ring nets.

FAD deployment

FAD deployment in Msambweni was conducted in December 2015. Prior to FADs deployment,

meetings were held at the four landing sites where BMU members were sensitized on factors to

consider in site selection and given an opportunity to propose locations for FADs deployment in

consultation with FADs experts from Mauritius (Atmanun Venkatasami and Neermal Dussooa).

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The factors included accessibility of the FADs by the artisanal fishermen, occurrence of tuna

and associated species, activities of ringnet boats and the probability of vandalism. BMU

members, FADs experts and staff from KMFRI and SDF&BE thus deployed four FADs at four

locations in Msambweni (Table 1).

Figure 1: Map of the study area.

Selection of data col lectors

Participatory approaches involving consultations with FADs development steering group

committee (SGC) and BMUs were adopted in the selection of data collectors. SGC was a body

mandated to review the progress of the FADs project as well as provide advice and technical

oversight. It encompassed government institutions and programmes (SDF&BE, KMFRI and

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KCDP) non-‐governmental organizations (CORDIO, COMRED and SmartFish) and community

representatives drawn from five landing sites. The requirements for selecting data collectors

were developed by SGC and included (1) have attained basic education (O-‐level education); (2)

ability to read and write; (3) familiar with local fishery; (4) basic knowledge of English and

Swahili language and (5) where possible inclusion of women. Meetings were held at each

landing site under the framework of BMU and catch monitoring activities explained first to the

BMU executive (BMU leaders) and later to BMU assembly (all BMU members encompassing

fishers, boat owners and traders). The requirements were presented to the BMU assembly and

two data collectors were selected from each landing site. A total ten data collectors (4 females

and 6 males) from the five BMUs were thus selected to participate in the FAD catch monitoring.

Table 1: Site information of four FADs deployed in Msambweni area (After Venkatasami and Dussooa, 2015) Landing sites (BMUs) Location Distance from

nearest shore (nm)

Depth

(m) Latitude Longitude

Gazi S 04˚27.448' E 039˚32.781' 2.6 63

Mwaembe S 04˚31.251' E 039˚30.728' 2.5 47

Munje S 04˚33.330' E 039˚29.769' 2.0 44

Mkunguni/Mwandamo S 04˚28.428' E 039˚32.095' 2.3 43

Training of data col lectors

The data collectors were trained on Fisheries information for improved artisanal fisheries co-‐

management module exploring the basics of fisheries monitoring, species identification and an

introductory course on data analysis notably catch per unit effort (CPUE) per gear, species

composition by gear and frequency of visits to particular fishing grounds. This was followed up

with a catch monitoring practical exercise, where the data collection forms were tried,

amended and adopted.

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Sampling strategy

Catches from the artisanal gears were sampled at five landing sites during three FADs

deployment phases: Pre-‐deployment (October – November), Colonisation (December –

January) and Post deployment (February – May) hereafter referred as Pre-‐FAD, Colonisation

and Post-‐FAD respectively. Electronic weighing balance, tape measure, data collection forms,

note book, pen, pencil, laminated sheets with colored images of prioritized pelagic species and

a fishing gear book (Samoilys et al., 2015) were distributed to each data collector to aid in catch

monitoring. Catch monitoring was done for three consecutive days under each lunar phase

(New moon, First quarter, Full moon and Last quarter) from November 2015 – May 2016. No

monitoring took place on days falling on Fridays due to religious and cultural consideration. A

CORDIO staff would take part in catch monitoring during every lunar phase.

Landed catch was weighed, individual fish identified, counted and their fork length measured

using a tape measure. In cases of large catch and where the fisherman or traders were in a

hurry, a randomly collected sub-‐sample would be measured. Data was collected through a

semi-‐structured questionnaire having two main components: [1] effort and catch data that

comprised of fisher’s name, crew size, vessel type, propulsion mode, area fished, fishing depth,

gear type, distance from FADs, nature of fishing, start and finish time of fishing, total weight of

catch, and total price; [2] biological data, which comprised of species name, fork length and

weight.

Priorit ized FADs associated species

Prioritizing the species to be monitored in the study was informed by a study by Moreno et al.

(2007) that lists the main pelagic fish attracted to FADs. They included skipjack tuna

(Katsuwonus pelamis), yellowfin tuna (Thunnus albacares), bigeye tuna (Thunnus obesus),

rainbow runner (Elagatis bipinnulata), dolphinfish (Coryphaena hippurus), wahoo

(Acanthocybium solandri), rough triggerfish (Canthidermis maculatus), striped marlin

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(Tetrapturus audax), black marlin (Makaira indica), blue marlin (Makaira nigricans), and oceanic

sharks, mainly silky sharks (Carcharinus falciformis). Other FADs related species were selected

based on known species taken in pelagic coastal waters in Kenya. They included eastern little

tuna (Euthynnus affinis), king mackerel (Scomberomorus commerson), queen mackerel

(Scomberomorus plurilineatus), giant trevally (Caranx ignobilis), black shark (Carcharhinus

melanopterus), swordfish (Xiphias gladius), tiger shark (Galeocerdo cuvier), great barracuda

(Sphyraena barracuda) and sailfish (Istiophorus platypterus). Species list and Identification

sheet were developed and used as reference material to data collectors.

Participatory mapping

Using the names of fishing grounds derived from catch monitoring, participatory mapping was

conducted using experienced local fishermen. The fishing grounds were mapped on flip charts

at four landing sites (Mwandamo, Mkunguni, Mwaembe and Munje). The boundaries of the

fishing grounds were later mapped by KMFRI using a handheld global positioning system in

form of geo-‐referenced points.

Data analysis

The impacts of FADs were assessed by analysing catch, effort and biological variables to derive

information on frequency of visits to FADs, changes in fishing duration, CPUE and income over

three FAD deployment phases of pre-‐FAD (October-‐November), Colonisation (December-‐

January) and Post-‐FAD (February-‐May). Frequency of visits to FADs was derived from the

information supplied by fishers with reference to the distance to FADs. These distance were

grouped into ascending classes from 250m, their frequencies determined and graphed using

bar graphs. Fishing duration was calculated as the differences in stop and start time of fishing.

Catch per unit effort was calculated using the formula:

𝐶𝑃𝑈𝐸 =𝐶𝑖𝐸𝑖

!!!!

𝑛

where Ci is the observed catch as number or mass (in kg) of fish caught by the ith group of

fishers interviewed, Ei is the observed fishing effort for the ith group of fishers interviewed, and

n is the number of fisher trips recorded throughout the survey period. Thus the unit for CPUE

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was kg/fisher/trip. Income of the fishers was calculated similar to CPUE only that the weight

was replaced by the total price of fish.

A detrended correspondence analysis was used to show the differences in abundance of pelagic

species of all the landing sites over the three FADs deployment phases. A One-‐way ANOVA was

used to test differences in CPUE, fishing duration and condition factor of prioritized pelagic

species across the FADs deployment phases. Length-‐weight relationship (LWRs) of the

prioritized species during the FAD deployment phases was also determined.

The information on participatory mapping was processed using GIS software (Arcmap 10.3) to

create spatial maps inform of polygons that matched the fishing grounds. The attribute table of

fishing grounds was populated with the number of visits and CPUE of hand line fishers to the

fishing grounds. Using Arcmap’s symbology tools, the frequencies of visits to fishing grounds

and CPUE at fishing grounds were displayed using graduated colors. The locations of FADs were

later overlaid on final map.

Results

Summary of sampling effort

Fishers operating at the landing sites in Msambweni use a variety of gears. Hand lines and

basket traps were the most sampled gears in all the landing sites (Table 2a). Of the gears

sampled, handlines, long lines, drift gillnets, set gillnets and ring nets were reported to operate

in fishing grounds around FADs. All these gears were drawn from all landing sites except ring

nets, which were only sampled at Gazi. The most popular fishing gears used by fishers at

Mwaembe were basket trap and spearguns. A total of 855 fishers were sampled during the

Post-‐FAD deployment phase as compared to 477 and 548 during Colonisation and Post-‐FAD

deployment phases (Table 2b).

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Table 2: Number of fishers sampled at the five landing sites in Msambweni grouped by fishing

gears and deployment periods.

Landing sites Gazi Mkunguni Munje Mwaembe Mwandamu All sites (a) Fishing gear Hand line 128 236 101 49 144 658 Drift gillnets 31 15 2 2 4 54 Set gillnets 15 1 10 28 4 58 Ring net 292

292

Basket traps 8 153 235 163 29 588 Long line

2

3 5

Spear gun 5 1 12 133 46 197 Monofilament 18

3 21

Purse seine 1

1 2 Cast net 3

3

Beach seine

1 1 (b) Deployment phases Pre FAD 123 41 114 114 156 548 Colonisation 158 50 105 68 96 477 Post FAD 216 147 189 194 109 855

Fishing duration

One-‐way ANOVA on pooled data of all landing sites showed significant difference in fishing

duration across the three FADs deployment phases (p<0.05). Fishing duration of hand line

fishers decreased in all the landing sites over the three deployment phases (Figure 2). The

overall reduction of fishing duration of hand line fishers in all the landing sites was 12%

between Pre-‐FAD and Colonization and 27% between Pre-‐FAD and Post-‐FAD. Other gears

notably ring nets, gill nets (drifting and set) and long lines showed marginal decrease between

Pre-‐FAD and colonization phases.

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Figure 2: Trends in fishing duration of different fishing gears used in Msambweni over three FADs deployment phases.

Catch per unit effort (CPUE)

Catch records on handlines were more relevant in showing the catch trends since the gear was

continuously monitored throughout the deployment phases. CPUE (kg/fisher/trip) of hand line

fishers showed an increase of >10% from the Pre-‐FAD to Colonisation in all landing sites except

Munje where there was a 30% decrease (Figure 3). There was a drop in CPUE from Colonisation

to Post-‐FAD in all landing sites, which was attributable to reduced fishing activities due to rough

sea. In general, CPUE trends of hand line and drift gillnet in Msambweni increased from the Pre-‐

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FAD to Colonisation phase but later dropped during the Post-‐FAD phase. Gill nets (set and

drift), ring nets and long lines showed fluctuations in CPUE. One-‐way ANOVA showed significant

difference in CPUE between the FADs deployment phases (p<0.05).

Figure 3: Trends in catch rates (kg/fisher/trip) of different fishing gears used in Msambweni during the three FADs deployment phases.

Income

An increase of 20% in the average income of hand line fishers of all the landing sites was found

between Pre-‐FADs and Colonization (Figure 4). The income decreased by 29% between the Pre-‐

FAD and Post-‐FADs. The decrease in income can be attributed to seasonal variation that

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reduced frequency of fishing activities during SEM period. There was a general decrease in

average income at Munje landing site throughout the three FAD deployment phases.

Figure 4: Trends in income (Kshs/fisher/trip) of different fishing gears used in Msambweni during the three FADs deployment phases.

Fork length, weights and relative abundance pelagic associated species

Prioritized pelagic species were caught by hand lines, gillnets, long lines and ring nets. A DCA on

their abundance showed differences in abundance over the three phases. Tetrapturus audax,

Carcharhinus melanopterus and Galeocerdo cuvier were captured more during Pre-‐FAD phases

as compared to Istiophorus platypterus, Caesio caerulaurea and Euthynnus affinis captured

during Colonisation (Figure 5). The Post-‐FADs phase was associated with Scomberoides tol,

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Istiophorus spp. and Sphyraena obtusata. Fine scale parameters including mean fork lengths

and mean weight of all prioritized species and other related pelagic species are provided in

Table 3.

Figure 5: Detrended Component Analysis of prioritized pelagic species caught by hand line

fishers operating at 5 landing sites of Msambweni during three FAD deployment phases.

Table 3: Mean fork lengths and weights of pelagic species caught over three FAD deployment

phases

Phases Pre FADs Colonization Post-‐FADs

Fish species Weight (kg)

FL (cm) Weight (kg)

FL (cm) Weight (kg)

FL (cm)

Acanthocybium solandri 10.0 110.6 3.5 72.3 8.0 110.1 Arius africanus

6.0 80.7

Caesio caerulaurea

0.3 24.5 0.3 25.7

Pre$FAD(

Post$FAD(

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Phases Pre FADs Colonization Post-‐FADs

Fish species Weight (kg)

FL (cm) Weight (kg)

FL (cm) Weight (kg)

FL (cm)

Caesio spp.

0.2 21.8 Caesio xanthonota

0.5 23.6

Carangoides ferdau 0.4 26.3

0.5 28.3 Carangoides fuscoguttatus

0.4 26.9 0.4 25.8

C. orthogrammus

2.2 31.9 Caranx ignobilis 2.0 43.4 3.0 47.3 2.2 45.7 Carcharhinus falciformis 6.6 102.2 3.0 101.1 2.0 92.1 C. melanopterus 92.8

Coryphaena equiselis 5.2 93.0 4.3 86.3 Coryphaena hippurus 4.1 91.9 4.0 81.1 3.8 76.5 Elagatis bipinnulata

0.8 39.7 0.3 22.8

Euthynnus affinis 1.7 47.1 2.1 50.6 1.4 40.3 Galeocerdo cuvier 2.3 57.1 11.0 113.5 Gnathanodon speciosus 0.2 25.3 0.5 29.8 0.5 30.9 Hemiramphus affinis

0.1 30.1

Hemiramphus far

0.1 30.0 0.2 31.6 Hyporhamphus affinis 0.1 28.4 0.1 28.9 Istiophorus platypterus 17.8 193.5 19.8 164.1 Istiophorus spp.

23.9 154.0 12.5 117.3

Katsumonus pelamis 3.2 56.2 2.5 52.2 1.7 48.3 Makaira indica

18.3 189.3 23.5 181.5

Rachycentron canadum 9.2 90.4 13.0 115.1 3.1 75.9 Rastrelliger kanagurta 0.2 21.6 0.2 21.3 0.3 23.7 Rhynchobatus djiddensis 1.4 59.4

1.2 95.9

Scomberoides tol

1.3 45.6 Scomberomorus cavalla 4.1 80.2 4.8 87.9 S. commerson 4.4 86.2 4.8 85.8 4.7 82.4 S. plurilineatus 2.7 68.3 3.0 70.9 2.9 70.4 Sphyraena barracuda 1.6 55.7 2.3 68.1 1.3 60.3 Sphyraena lewini 1.3 67.5 3.0 101.2 7.5 93.1 Sphyraena obtusata 0.8 34.7 0.4 29.8 0.2 27.0 Thunnus albacares 7.3 81.0 6.1 71.4 6.4 74.4 Thunnus obesus 6.6 74.2 3.6 61.8 4.6 122.6 Tylosurus crocodilus 1.0 81.8 0.6 71.8 1.1 85.6 Xiphias gladius 2.8 48.1 2.6 53.6 1.0 36.1

The estimated parameters of the length-‐weight relationship (LWRs) of five prioritized species

consistently abundant during the FAD deployment phases having both length and weight data

15

are given in Table 4. All LWRs were significant (p < 0.01), with r2 values greater than 0.8. ANOVA

indicated condition for the prioritized species did not significantly vary between the different

FAD deployment phases (p=0.1934).

Table 4: Length weight relationship parameters showing the b-‐value, which is the measure of isometry and r2 showing the level of association between length and weight, of consistently abundant pelagic species sampled Species b r2 Sample size (n) Katsumonus pelamis 3.221 0.8799 18 Thunnus albacares 3.633 0.8443 75 Thunnus obesus 3.102 0.9330 32 Elagatis bipinnulatus 2.334 0.9421 40 Acanthocibium solandri 2.491 0.9751 16

Frequency of vis its to FADs

During Colonisation phase fishing near FADs (<250 m) was found to be more frequent than

Post-‐FAD deployment phase (Figure 6). The visits near FADs (<250m) were few in Munje and

Mwaembe. Fishers from Munje did not report fishing near FADs during both Pre-‐FAD and Post-‐

FAD phases. This can be partly attributed to the relatively low proportions of hand line fishers

and high proportion of non-‐motorized vessels (canoes) that made it difficult to venture into the

FADs fishing grounds. Increase in the frequency of visits to FAD was consistent with ease of

access to fishing grounds around FADs especially during Post-‐FAD phase, which was coherent

with rough sea experienced during southeast monsoon. The trend was different in Mwandamo,

as the number of visits to FADs reduced from colonisation phase to Post-‐FADs phase. This is

likely to be due to their accessibility to two FADs in Gazi and Mkunguni.

16

Figure 6: Changes in the frequency of visits around FADs by landing sites over three deployment phases.

Fishing zones around the FADs

Participatory mapping established the fishing grounds around FADs were: Madzivikwe, Singani,

Kwale, Mwakikuye, Mboe and Ushini. The four FADs were deployed in shared fishing grounds

especially because they are located offshore. The number of visits by hand line fishers was

more at fishing grounds near Mwaembe FAD. However the CPUE was higher at fishing grounds

near the Mkunguni/Mwandamo FAD (Figure 7).

0

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250 500 750 1000 2500 5000 7500

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uency of visits

Distance from FADs (m)

All landing sites

Colonisation Post FAD

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uency of visits


GaziColonisation Post FAD

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uency of visits

Distance fro FADs (m)

MwandamoColonisation Post FAD

051015202530354045

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uency of visits

Distance fro FADs (m)

MkunguniColonisation Post FAD

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MwaembeColonisation Post FAD

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17

Figure 7: Number of visits and catch rates of hand line gears at fishing ground in relation to FADs location in Msambweni.

Discussion

Fishing duration is a function of fishing effort. Most of the fishing time is spent moving from

one fishing ground to another in search for fish. Since FADs aggregate fish in one area it is

expected that the fishing duration should reduce significantly after FADs are deployed and

colonized. FADs have a potential of reducing effort and in turn minimizes the cost of fishing

operation. It is therefore noteworthy that the fishing duration for fisher operating hand lines

decreased in all the landing sites over time during the 8 months of catch monitoring. There are

other confounding factors such as rough sea, which can significantly reduce fishing activities

and concentrate fishermen to the nearshore fishing grounds thereby reducing their fishing

duration. However these actions could be debated but were fairly justified by many fishermen

during the feedback meetings held in all the five landing sites where the monitoring was done.

a) Number of visits b) CPUE

Gazi%

Mkunguni%

Mwaembe%

Munje%

Gazi%

Mkunguni%

Mwaembe%

Munje%

18

Accessibility to the fishing grounds around FADs was a factor that contributed to variation in

catches across the deployment phases. Low CPUE was recorded during the Post-‐FADs that

coincided with the southeast monsoon season. Most fishers in Msambweni area are artisanal

fishers and therefore use vessels such as canoe that cannot venture far from the shore

especially when the sea is rough. Therefore catches are bound to decline as a result of reduced

fishing activities due to rough sea resulting from a seasonal changeover from northeast

monsoon to southeast monsoon.

Fishing around FADs was dependent on seasons as opposed to reasons such as fish behaviour

(e.g. Hallier and Gaertner, 2008) and probably many fishers could have fished around FADs had

the sea been calm and/or owned vessels that could venture into the deep sea. Validation

meetings affirmed that rough conditions and lack of vessels were an impediment to fishing

offshore. However as the demand at local hotels and restaurants for pelagic species continue

to increase; the number of commercial fishers venturing out to target pelagic fish is bound to

increase. Indian Ocean Tuna Commission (IOTC) has set an exploitation tonnage per species,

which if exceeded in long-‐term would put the fisheries stocks at risks of decline (ISSF, 2013).

Caution should be taken to prevent fishing of already overexploited pelagic species such as

Yellowfin tuna (Thunnus albacares), which is 94% overexploited, Striped marlin (Tetrapturus

audax), which 60% overexploited, and Narrow-‐barred Spanish mackerel (Scomberomorus

commerson) (IOTC, 2015).

Estimates on Income derived from the fishery are a reflection of the fishery contribution

towards the livelihood of the fishing communities (Allison and Ellis, 2001). The change in

income during the FADs monitoring period may be attributed largely to seasonal variation in

catch rates as opposed to aggregation of fishes around FADs. A cost-‐benefit analysis is needed

to ascertain the net return from the FAD fishery since part of gross income is used to pay for

the cost of fishing operation including vessel maintenance and repair.

19

The condition factor of six prioritized species did not significantly vary possible because of

inadequate information on the size structure. The parameters of the length–weight relationship

can vary significantly according to sex and season or due to other factors such as feeding rate,

growth phase, habitat and health (Bagenal and Tesch, 1978; Hossain et al., 2006), all of which

were not accounted for in the present study. However, the results can serve as baseline data

for species without previous information on length–weight relationships and for comparison

with future studies.

Conclusion and lessons learnt

There is an indication of increased CPUE and income of hand line fishers after deployment of

FADs. However reduced fishing activities during Post-‐FAD deployment phase, limits our

conclusion of fully assessing the impacts of FADs on catches. Fishing duration of hand line

fishers has also decreased since FAD deployment. However it is still difficult to ascertain

whether FADs contributed to these changes. Most of the monitoring was done during NEM

(November – April) as opposed to SEM (May) and therefore catch monitoring in both NEM and

SEM is still needed. The influence of seasons on fishing activities limit further deductions on

observed CPUE, income and visits to FADs fishing grounds.

Fishermen are keen to venture into the FAD fishery following an increase in the frequency of

visits to fishing grounds around FAD (<250m). The utilization of FADs indicates that awareness

of the FADs fishery was well received across the fishing fraternity resulting in fishers frequently

making fishing trips to FADs. The type of artisanal vessels and gears may be limiting access to

FAD fishing grounds particularly at Munje and Mwandamo landing sites. The intensity of fishing

around FADs decreased during the Post-‐FAD suggesting access to FADs is limited by the

seasonal changes, fishing vessels and gear type.

All the five BMUs were receptive to catch monitoring and future projects should build on this.

Catch monitoring to measure the impact of FAD fishery is still required. Fishermen are keen to

venture into the FAD fishery but there is need for constant awareness across the fishing

20

fraternity. More importantly is personalised or on-‐site training on species identification and

piloting of open data kit using smartphones to help reduce the time spent in processing the

data is essential. Training on offshore fishing vessels for fishermen would still be required

through training of trainers.

While the FADs project in Kenya seeks to optimize benefits flowing from offshore fishing

through increased catches, Caution should be taken in promoting fishing of already

overexploited pelagic species such as Yellowfin tuna (Thunnus albacares), which is 94%

overexploited, Striped marlin (Tetrapturus audax), which 60% overexploited, and Narrow-‐

barred Spanish mackerel (Scomberomorus commerson). This could include measures such as

species restrictions.

21

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