Ayungon and Bindoy, Negros Oriental

Determining harvest control reference points for near shore resources targeted for livelihood-linked approaches to sustainable fisheries in RARE project sites

Wilfredo L. Campos

Kim P. Nunez Donna M. Guarte

Melsie C. Cadenas Mary Ann Cielo L. Malingin

Ryan Dexter Piloton Lucas R. Felix

OceanBio Laborarory Division of Biological Sciences, College of Arts & Sciences University of the Philippines Visayas, Miag-ao, Iloilo 5023 Philippines Final Report

submitted to

RARE Philippines, Inc.

University of the Philippines Visayas Foundation, Inc.

Miag-ao, Iloilo November 2016

A. Introduction

RARE is implementing a GDA-funded project called “Harnessing Markets to Secure the Future of Near Shore Fishers” in various areas in the country with the overall goal of supplying high-valued species to high-end restaurants and hotels with fish caught from responsible fishing and proper post-harvest practices. To meet this goal, several conditions must be met including: viability of the supply; sustainability of harvesting; quality of post-harvest practices; and maximizing of benefits from the source to the market. Critical to determining these conditions is assessing the status of the stocks and their fisheries.

This study was implemented to provide a quick assessment of the stocks of target resources in the various project areas of RARE with the following objectives:

a) Compile and identify gaps in relevant scientific information on pre-identified target species b) Conduct initial site surveys to verify target species and determine what and where to monitor and collect samples c) Design a fisheries monitoring and catch sub-sampling scheme d) Train field data recorders (enumerators) and field assistants e) Determine Harvest Control Reference Points f) Recommend measures to ensure sustainability of the target species

B. Materials and Methods

Monitoring of fisheries catch and effort as well as biological subsampling of catches were conducted in (i) Culasi, Antique, (ii) Camarines Sur Occidental Mindoro Ayungon and Bindoy, Negros Oriental, (iii) Looc and Lubang, Occidental Mindoro, (iv)

Cantilan and Cortes, Surigao del Sur and Antique

(v) Tinambac, Camarines Sur (Fig. 1). The Negros Oriental

Surigao del Sur duration of monitoring ranged from two (2) to three (3) months, starting from April to July 2016. The general methods common to all sites are presented below, while specific methods are presented Figure 1. Map showing the location of areas separately for each site. monitored by RARE. sites.

B.1. General Methods

The sequence of methods shown below (Fig. 2) was followed at each of the 5 sites:

Figure 2. Flow chart showing how the monitoring and biological sampling schemes of the study were designed.

B.1.1. Initial site visits were done to conduct FGDs and to meet with LGU staff and RARE local teams. The purpose of the FGDs were to validate the information on target species and barangays to monitor, which were initially provided by RARE field staff and the LGUs.

Additional information gathered included specific fishing areas by gear type, landing sites and time, and a rough idea of number of fishers by target gear type.

B.1.2. Design of catch and effort monitoring and biological sampling schemes. After verifying information on most commonly-caught species, the gear types used to catch them, and where these gear types were operating from, monitoring sites and frequency of sampling were determined. In general, catch and effort for target species and gear types were monitored daily in at least 3-4 sitios in each of the 5 sites. Size measurements of about a kilogram of each target species in catches of the target gear types were done weekly, whereas samples for processing and examination in the lab were purchased also once per week.

B.1.3. Hiring and training of enumerators and field assistants (FA). In most sites, both enumerators and field assistants were recommended by the RARE local team and or the LGU (MAO). Both were trained to do their respective tasks during the initial visits to the sites. A detailed description on the scope of the training is presented in Figure 2. Enumerators were trained to record catch (kgs) and effort (number of fishers & fishing trip duration) of at least 5 operators (fishers or groups of fishers depending on gear) by gear type every morning. These and other related data were recorded in notebooks following the format and the guidelines shown in Fig. 4. In addition, enumerators measured specimens of target species (following Fig. 3) from catches of assigned gear types once a week. They also arranged for the regular scheduled purchase of samples from the fishers at the various monitoring sites. Isda Pusit

Figure 3. Different ways of measuring fish (isda ) , squid ( pusit ) and octopus ( pugit a).

Field assistants, on the other hand, required a bit more skills and training. They did the initial processing of specimens from the field. These included verification of taxonomic identification of specimens from purchased samples, measurement of lengths and weights, and at least for some target species, determined gonad development stage following pictorial guides such as Fig. 5. After this initial processing, FAs dissected off the head, gonad and guts of each identified specimen, stored these in labeled plastic containers with 10% buffered seawater-formalin solution, packed and prepared the specimens for transport to the lab in

Miag-ao. In addition, since the FAs were also present during the enumerators’ training, they were also tasked with checking the catch and effort records kept by enumerators for inconsistencies and errors. FAs were provided with adequate funds to cover supplies needed for the initial processing of samples and transportation to cover all the sitios covered by the monitoring/sampling scheme.

b c

Figure 4. (a) Catch and effort format, (b) s ample recording of catch and effort, and (c) some notes on proper recording of catch and effort.

Figure 5. Example of male and female gonads ( Decapterus macrosoma ) showing the different stages of maturation. Sizes in the pictures are proportional.

B.1.4. A second site visit was conducted about 1 month after the initial visit to further check on the recording of catch and effort and to correct any errors, to ensure that biological sampling and processing by field assistants was in accordance with what they were trained

to do, and to collect the monitoring records and biological samples for transport to the lab in Miag-ao. Samples in subsequent weeks were sent to the lab for validation and further analyses (e.g. species, sex and gonad maturation, gonad weight measurement).

B.2. Harvest Control References

The short duration of the study poses limitations to the resulting estimates. Because not all seasons were monitored, and because many biological processes, such as maturation, spawning, recruitment and growth, are seasonal, the data may fall short of representing the status of the stock. To reduce these constraints, we supplement our estimates with those from other published work which covered longer study periods. In addition, data from monitoring under the RARE Fish Forever Program in two areas were made available to supplement data from this study. With these measures, we provide best estimates based on available data.

After all the field and laboratory processing and data analysis, the fisheries and biological data are summarized and presented as harvest control references.

B.2.1 Size distribution of catches

This reflects the lengths of target species caught by the monitored gears during the study. Size frequency histograms are presented for each gear type to check for differences in size selectivity. This allows for formulating interventions that are specific to certain gear types and not necessarily to all. For example, if catches from a certain gear are dominated by small individuals (e.g., juveniles), regulations can be limited to only those gear types.

B.2.2. Size at sexual maturity

Histograms showing gonad maturity stage proportions by size class for each target species (across all gear types monitored) were constructed to show at what size the onset of maturity

sets in (i.e., the size of the smallest mature individual recorded, here in called Lm). The proportional distribution of mature fish across all size classes represents that portion of the stock that is able to spawn or what is called the spawning potential. The data were used to construct a cumulative frequency ogive, which in turn allowed estimating the “size at first

maturity” (L m50), or the size at which 50% of fish at that size are mature. The GeoGebra

software was used to construct the ogive. Lm50 has been used as a reference point for stock sustainability.

B.2.3. Growth

The age at which the target species matures becomes an important reference point especially in heavily-fished fishing grounds, where fish are typically caught before they reach the age of maturity. Age can be estimated from size data if the population’s growth is known. Since this study was designed to cover only 2-3 months, it was not possible to construct growth models for any of the target species. For many of them, however, growth models from

different fishing grounds and from different years, are available from various reports and studies, including Ingles & Pauly (1984), Corpuz et al. (195), Lavapie-Gonzales et al. (1997) and Froese & Pauly (2016). For those without any available information, published growth curves for closely-related (congeneric) species were used as approximations. Aside from providing estimates of age, the parameters L and K of the Von Bertalanffy Growth Model (VBGM), together with estimates of the instantaneous natural mortality rate (M) are used in reconstructing the stock’s spawning potential (explained in next section). M is usually estimated when deriving total mortality rate of the stock. Again, the short duration of the study did not allow any mortality estimates. Since estimates of M are generally even less available than the growth parameters, it was estimated for most target species in the study using the general formula of Pauly (1980), relating natural mortality to growth and average ambient water temperature in the fishing ground:

log M = -0.0066 – 0.279logL + 0.6543logK + 0.4634logT

where: M = instantaneous natural mortality rate (annual)

L = asymptotic length of the VBGM K = growth coeeficient of the VBGM T = annual mean water temperature in the fishing ground (oC)

B.2.4. Length-Based Spawning Potential Ratio (SPR)

As mentioned above, the length-based spawning potential of a stock is defined by the size or age distribution of mature fish. The spawning potential ratio (SPR) is the fraction of the stock’s spawning potential that is not caught by the fishery (and therefore allowed to spawn). Hence, in an unfished stock, the SPR is 100% while values range from 0 – 100 for fished stocks. The more the overlap between the size distribution of fish caught by the fishery (including all gear types) and the size distribution of mature fish, the less the spawning potential left in the stock. SPR values between 20 – 40% are generally acceptable as sustainable for fished stocks.

Actual SPR values based on size, maturity (Lm50), growth (K, L ) and natural mortality (M) data gathered on the target species were estimated using a web-based software accessible at http://barefootecologist.com.au/lbspr. Actual estimates of SPR are a function of the size

distribution (represented by Lc, the size at which 50% of all fish at that size are caught by the fisheries) of fish in the catches. Hence, when the resulting actual SPR was below the set target minimum limit of 20%, the input size distribution was adjusted by sliding from one to several

size classes to the right (i.e., by increasing Lc) until the minimum 20% SPR was attained. This

necessarily corresponded to a larger Lc value which serves as the target “length at first capture”.

B.2.5. Catch and effort data

Daily records of catch (C) and effort (f) were summarized to give estimates of mean values for catch rate (kgs/fisher/trip), number of fishers per trip and number of hours fishing per trip by fishing gear. Because stocks of targeted species are widely distributed, those species targeted

by neighboring barangays or even municipalities are from the same stock. For this reason, C and f data for sites with common targets were pooled (by gear type) before the analysis. In this study, the term “fishing trip” includes going out to the fishing ground, actual fishing, and then returning to land the catch. In this study, all the targeted gear types in the various sites had one trip per day. Also, the term “catch rate” is used in this report in place of “catch per unit effort” to avoid confusion. The mean number of fishing days per month was computed per target fisher by gear type (at least 5 per barangay). This fishing frequency to multiply the total number of units of the targeted gear type, which the enumerators and the field assistants estimated thru interviews throughout the study, to estimate total fishing effort for the study period by gear type. The reason for keeping the number and identity of target fishers fixed (as much as possible) was to ensure reliable estimates of fishing frequency. The latter is important in providing estimates of total catch (= supply) as this reflects the market viability of the target species.

The total catch by target gear types for the months covered by the study is:

= Kg/fisher/trip X no. of fishers/trip X no. of fishing days/months X no. of months covered by the study

Annual catch (Cann) can be derived by multiplying the first 3 values above by 12 months, instead of the months covered by the study. However, this estimate assumes that the target species and the gear used to fish them are locally present in similar abundances throughout the year. Any seasonality in their abundance would invalidate this estimate.

Lastly, field enumerators and assistants were instructed to categorize catches into local names of the target species, with all catches of non-targets lumped into the “others” category. In sites where closely related species were difficult to differentiate in the field (e.g., clupeids and some siganids), the local common name for the group was used. These data were used to derive the species composition of catches in the study site.

B.3. Site-specific Methods

B.3.1. Monitored sites

The figures below show the zoned map used in the monitoring in Ayungon and Bindoy, Negros Oriental. Zoning was done to show where fishing gears usually operate. Barangays Iniban, Awa-an, Tampocon II and Anibong (yellow font) were monitored in Ayungon, while barangays Tinaogan, Domolog, Cabugan and Malaga (yellow font) were monitored in Bindoy. All 8 barangays were monitored for catch and effort and biological sampling. The duration of the monitoring was from May 5 - July 5, 2016.

Figure 6. The zoned map of Ayungon and Bindoy, Negros Oriental used in the monitoring. B.3.2. Target Gears and Species

The target species as well as the target fishing gears initially monitored in Ayungon and Bindoy are show in Table 1. Target species initially selected for monitoring included 7 species of sardines (Family Clupeidae), Amblygaster sirm, Dussumiera elopsoides, Herklotsichthys quadrimaculatus, Sardinella albella, S. lemuru and Spratelloides gracilis, 4 species of anchovies (Family Engraulidae), Atherinomurus regina, Encrasicholina heteroloba, E. punctifer and Stolephorus waitei, 2 fusiliers (Family Caesionidae), Caesio cunning and C. caerulaurea, 2 siganids (Family Siganidae), Siganus fuscescens and S. spinus, 1 scombrid (Family Scombridae), Rastrelliger kanagurta, 1 carangid (Family Carangidae), Selar crumenophthalmus and 2 squids, Stenoteuthis oualaniensis (Family Ommastrephidae) and Thysanoteuthis rhombus (Family Thysanotheutidae). The initially monitored gears on the other hand were bottom set gill net, hook and line, beach seine and scoop net. For hook and line, this included 3 types or modifications of the gear such as multiple hook and line, multiple hook and line for Selar and hook and line for squid. In general, selection of target species and gears were based on the information provided by RARE local team, LGU and result of the focused group discussions conducted during the first visit. After the initial 2-3 weeks of monitoring however, it was clear that some of the initially targeted species were not very well represented in the catches of targeted gears, hence, were no longer included in the final list. These are Sardinella albella, S. fimbriata, S. lemuru, Amblygaster sirm, Spratelloides gracilis, Atherinomurus regina, Stolephorus waitei, Caesio cunning and Siganus spinus. For the final list of target gears, other gears that catch considerable amount of target species were included. These are fish corral, jigger, drift gill net, modified jigger for giant squids and spear.

B.3.3. Biological Sampling

Catches of target species from the various gear types were subsampled regularly at each site. Measurements (SL) of target species caught by the monitored gear types were done once a week (30-50 individuals per target species per gear). In addition, 1-2 kg of specimens per target species were purchased from each gear type every week. These samples were brought back to the lab at UPV in Miag-ao for verification of species identification, determination of gonad development stage, and measurements of other parameters.

Table 1. List of target fishing gears and species monitored in Ayungon and Bindoy, Negros Oriental. TAXA Bottom set Hook Beach Scoop Fish Jigger Drift Jigger (for Spear gill Net & Line Seine Net Corral Gill Net giant squids) Clupeidae (Sardinas)* 2 1 2 2 Engraulidae (Bolinao)** 1 2 Rastrelliger kanagurta (Anduhaw) 2 2 2 Selar crumenophthalmus (Tamarong) 1 &2 1 & 2 1 & 2 1 & 2 Sthenoteuthis oualaniensis (Lumayagan) 1 & 2 1 & 2 Thysanoteuthis rhombus (Dalupapa) 1 & 2 1 & 2 1 & 2 Caesio caerulaurea (Dalagang 2 2 Bukid/Sulig/Solid) Caesio cuning (Ulan-Ulan) 2 2 Siganus fuscescens (Danggit) 1 1 Siganus spinus (Danggit Kubolon) 1 1

1 – Ayungon; 2- Bindoy

X - original fishing gears for monitoring X - supplementary gears for monitoring

*Clupeidae (Sardine) species: Amblygaster sirm, Dussumieria elopsoides, Herklotsichthys quadrimaculatus, Sardinella albella, Sardinella fimbriata, Sardinella lemuru, Spatrelloides gracilis

**Engraulidae (Bolinao) species: Atherinomurus regina, Encrasicholina heteroloba, Encrasicholina punctifer, Stolephorus waitei

C. RESULTS

The results of the analyses are presented by species. The sequence of results presented is as follows: general biology and geographical distribution, size distribution, gonad maturity stages, growth and spawning potential ratio.

C.1. Selar crumenophthalmus (tamarong)

C.1.1 General Biology

Selar crumenophthalmus or the big eye scad (Family Carangidae) is one of the most important small pelagic species in coastal fisheries. The juveniles and adults are commonly caught up to 24cm FL by hook and line, beach seines, trawls, purse seines and traps, with the juveniles sometimes used as baits for tuna, while both adults and juveniles are marketed Figure 7. The target species Selar crumenophthalmus. as fresh and salted or dried in the markets.

S. crumenophthalmus is circumtropical from Indo-Pacific (East Africa to Rapa, north and southern Japan and the Hawaiian Islands, south to New Caledonia), Eastern Pacific (Mexico to Peru, including the Galapagos Islands), Western Atlantic (Nova Scotia, Canada and Bermuda through the Gulf of Mexico and the Carribbean to Sao Paulo, Brazil) and Eastern Atlantic (Cape Verde to southern Angola). The species usually travel in compact groups of hundreds or thousands individuals. The adults and juveniles prefer clear oceanic waters around islands to neritic waters, and occasionally in turbid waters. The species is mainly nocturnal, with groups or schools dispersing at night to feed inshore on small shrimps, benthic invertebrates and forams or offshore on zooplankton and fish larvae (Froese & Paul6, 2016).

S. crumenophthalmus sexually matures at 16.61 – 17.3cm SL (Lm50) (FSP, 2002; Olano et al., 2009), with spawning extending a period of 6 – 7 months. In US Virgin Islands, spawning is between March - September (Tobias, 1987), April - September in Hawaii (Clarke & Privitera, 1995), and April - November in Indian Ocean (Roos et al., 2007).

C.1.2. Size Distribution

Size distribution of the target species caught by bottom set gill net and hook and line off Ayungon and Bindoy, Negros Oriental during the monitoring period (May-July 2016) is presented below in Figure 8. Length measurements used in constructing the size distribution frequency graphs were from biological samples and additional measurements by field

enumerators. The estimates of length at maturity Lm50 (this study and from literature) are also indicated in the graphs.

A total of 3,188 fish individuals were measured within the 2-month monitoring period. The smallest individual caught measured 5.1cm SL while 21.5cm SL was the largest (Figure 8). Of the catches, 55% were above the estimated size at maturity

(Lm50, see section below). This indicates that most S. crumenophthalmus are already mature when caught or may have already spawned.

Estimates of Lm50 from stocks in the Camotes Sea (FSP, 2002) and Lagonoy Gulf, Bicol (Olano et al., 2009) are also indicated for comparison.

A comparison of catches by gear shows that gill nets catch smaller and immature individuals, with 92%

below the Lm50 (Figure 10). This clearly shows how selective gill nets are. Only those fish that are small enough to fit the mesh are caught. The larger individuals bump into the net but are not readily entangled. In contrast, catches of hook and line are mostly mature, with ~70% above the Lm50. Hook and line is a passive gear, and hence, not size-selective. The high proportion of larger fish may also be the result of some hook and line fishers operating in deeper areas where the larger fishes are found. This, however, needs to be verified through continued monitoring since possible difference in catches between shallow and deeper waters opens opportunities for management interventions.

C.1.3. Gonad Maturity Stages and Maturation Curve

A total of 328 S. crumenophthalmus individuals were examined for gonadal staging, with size ranging from 11.5 - 21.5cm SL. Of these, 70% (=231 individuals) were in mature and spent stage, covering the size range 13.5 - 21.5cm SL. The rest of the samples were immature (30% or 96 individuals). Between gears showed that hook and line catches were mostly mature, with the smallest class size recorded (13.5cm SL) already in the mature and spent stage. This is based on a relatively large sample size (n=244). Catches of gill nets on the other hand were mostly immature which may be attributed to its selective nature. According to Tobias (1987), Clarke & Privitera (1995) and Roos et al. (2007), spawning season of the species is between March - November, with a peak around September - November. The monitoring started in May and is within the spawning season, hence, relatively higher number of mature individuals were sampled.

Figure 10 shows the maturation curve or ogive of S. crumenophthalmus in Ayungon and Bindoy with the derived

values from Lm50 and Lm95, which are needed in estimating the spawning potential ratio of the stock. Based on the ogive, length at which 50% of the

population matures (Lm50) is about

15.59cm SL while Lm95 is at 17.37cm SL.

Compared to the Lm50 estimates in Lagonoy Gulf, Bicol (17.30cm SL, Olano et al. (2009) and in the Camotes Sea (16.61cm SL, FSP, 2002), the current estimate is smaller. It should be noted

that the ogive and resulting Lm50 and Lm95 are dependent on the input length, maturity data, and monitoring period, 14 i.e. there may be months with more mature fish and wide size ranges, and months with less catches and narrower size ranges. The corresponding estimates of Lm50 will differ under these three scenarios.

C.1.4. Growth Curve

When length data are limited to a few months, relative age at a given length can be estimated provided that a growth equation (e.g., VBG Model) for the same species has been constructed (from another area, or from previous years). Ageing studies based on analysis of otoliths (fish) or statoliths (squid) may be too time consuming and costly for most multispecies stock assessment studies, but age at length/stage data may provide insights on the stock that could otherwise be masked by high variability in length data, particularly in heavily-fished stocks.

Figure 11 shows the growth curve of S. crumenophthalmus which may be used in estimating the ages of mature specimens and or the age of individuals of any given length. Information used in constructing this curve such as growth coefficient k (1.2) and L∞ (28.44 SL) were obtained from various studies from Ingles & Pauly (1984), Dazell & Penaflor (1989), Dwipongo (1986) and Olano et al., (2009). The corresponding range of ages of the catches (5.1-21.5cm SL) is from 2-13 months, with most between the ages of 8-10 months (15-18cm SL). According to the studies previously mentioned above, S. crumenophthalmus can reach a length of 28.44cm SL. This indicates that S. crumenophthalmus in Ayungon and Bindoy, Negros Oriental are caught relatively young, and are not able to grow their maximum lifespan. Based on the growth curve, the corresponding ages of the smallest mature (13.5cm SL) individual recorded in the study and the estimated Lm50 (15.59cm SL) and Lm95 (17.37cm SL) are about 6 months, 8 months and 9.5 months, respectively.

C.1.5. Length-Based Spawning Potential Ratio (LB-SPR)

Spawning potential ratio (SPR) is the proportion of the total spawning potential (derived from the size range of mature fish, Lm50 to Lm95) of fish remaining in the population after removing all fish caught by the fishery. Hence, an unfished stock would have an SPR of 100%, while very intensely-fished stocks would have an SPR close to 0%, because all mature fish would have been removed or all female fish would have been caught by intense fishing.

Hence, estimates of actual SPR of currently fished stocks are dependent on the (i) size distribution of fish in the combined catches, and (ii) the proportion of all mature fish in the stock (indicated by location of Lm50 on size distribution) that are caught. SPR is computed using estimates of natural mortality (M), the growth coefficient (K), asymptotic length (L),

length when 50% (Lm50) and 95% (Lm95) of the population becomes mature, and the actual size frequency distribution of catches from the fishery. Values for M, K and L were either cited or derived from the literature. By adjusting the size distributions of the catches, recommended

values for SPR (20-40%) can be targeted. Lc or length when 50% of the population is captured may then serve as the harvest control measure to attain the targeted SPR. Table 2. Estimated spawning potential ratio of Selar The estimated SPR of S. crumenophthalmus in Ayungon and Bindoy, Negros crumenophthamus caught in the fishery in Oriental Ayungon and Bindoy is shown in Table 2.

Lc (cm SL) L50 (cm SL) Spawning Potential At present, SPR of the stock based on the 2 Ratio month monitoring data is 11.0%. To increase 20.09 (actual) 15.32 11.0 % the SPR of S. crumenophthalmus to at least

20.90 17.32 21.0 % 20-36%, the L50 or median of the projected 22.44 18.32 36.0 % size distribution of fish in the catches should be set at 17.32-18.32cm SL, respectively. This means that catches smaller than these sizes should be banned. Again, the SPR estimates are based on the 2 months of monitoring only. The study of Erisman et al. (2014) in California showed that SPR estimates increases with increasing spawning frequency. Hence, SPR of S. crumenophthalmus in Negros may improve if monitoring will be conducted during the spawning season (April through November).

C.1.6. Harvest Control Reference Point

Based on the results of the 2 month monitoring the following are recommended:

• Shift in gear use from gill nets to hook and line. Gill nets are catching juveniles while hook and lines are catching larger (mature) individuals.

• For gill nets targeting S. crumenophthalmus, the mesh size should be increased to allow smaller/younger fish to pass through the net. Based on the results of this study, size limit should be >17cm SL to increase the SPR of the species to 20 or 30%. This can allow enough individuals to spawn before they are caught.

• Fish buyers should also be informed of the above recommendations. And it would be better if fish buyers will be instructed to buy S. crumenophthalmus that are equal to or greater than the size limit only. By doing so, fishers will be discouraged in catching smaller individuals (no market for smaller individuals = no harvest of smaller individuals).

C.2. Rastrelliger kanagurta (anduhaw)

C.2.1. General Biology

The Indian Mackerel, Rastrelliger kanagurta (Fig. 12) is an epipelagic, neritic species occurring in areas where surface water temperatures are at least 17° C, and schooling is usually related 16 to size. Its maximum fork length is 35 cm, and commonly caught up to a size of 25cm FL (Froese & Pauly, 2016).

The spawning season of R. kanagurta around India seems to extend from March through September. It spawns in several batches. Juveniles feed on phytoplankton (i.e. diatoms) and small zooplankton such as cladocerans, ostracods, larval polychaetes, etc. With growth Figure 12 . The target species Rastrelliger kanagurta they gradually change their dietary habits, a process that is reflected in the relative shortening of their intestine. Hence, adult Indian mackerel prey primarily on macroplankton such as larval shrimps and fish. Longevity in R. kanagurta is believed to be at least 4 years (Carpenter & Niem, 2001). C.2.2. Size Distribution 111 R. kanagurta were measured within the 2 - month monitoring period. Lm50 =17.29cm Lm50 =20.01cm The smallest individual ( Culasi, 2016) ( this study ) caught by bottom set gill net measured belongs to size class 11.5 cm SL while the largest belongs to 23.5 cm SL. Of the catches, ~89% are below the estimated L m50 (20 .01 cm SL, see Gonadal Figure 13 . Size distribution frequency of Rastrelliger kanagurta caught in Maturation and Maturation Ayungon and Bindoy, Negros Oriental from May – July 2016 . Note: L m50 is the size when 50% of the population mature Curve section for explanation of Lm50). This indicates that R. kanagurta are mostly immature when caught. Modal length for this species belongs to size class 15.5 cm SL.

C.3.3. Maturity Stages and Maturation Curve

A total of 21 R. kanagurta individuals were examined for gonadal staging. The smallest size examined measured 19.5cm SL while 24.5cm SL was the largest (Fig. 14a). Out of 21 individuals, 16 were mature or 76% of the total biological samples. Size of mature individuals ranged from 20.5- 24.5 cm SL. The rest of the samples were immature. The spawning season of the species is from March to September (Carpenter & Niem, 2001), although peak recruitment months in various fishing grounds in the Philippines is in August-September (Campos et al., 2013). The latter suggests that peak spawning in the country is from June to

July. The monitoring covered the months of April-July, which fall within the spawning season of the species thus, 76% of the individuals sampled were mature.

Based on the ogive, length at which 50% of the population matures (Lm50) is about 20.01cm

SL while Lm95 is at 20.22cm SL. Compared to the Lm50 (17.29cm SL) estimate of a parallel study in Culasi (2016), Lm50 estimate in Ayungon and Bindoy is higher but within the range of the reported Lm50 of Olano et al., 2009 (19-23 cm SL). But note that ogive and resulting Lm50 and

Lm95 are dependent on the input length mature data, i.e. there are months when larger individuals caught are larger in size which will result to larger Lm50 and months when catches are smaller in size resulting to smaller Lm50.

C.2.4. Growth Curve

The corresponding range of ages of the catches (11.5-23.5cm SL) is from 4-13 months, with most between the ages of 6-7 months (15.5cm SL). According to Froese and Pauly (2016), R. kanagurta can reach a length of 38.0cm TL (= 33.9cm SL) and a maximum reported age of 4 years. This indicates that R. kanagurta in Ayungon and Bindoy are caught while relatively still young, and are not able to grow to their maximum lifespan. Based on the growth curve (Fig.

15), the age at Lm50 (20.01cm SL) and Lm95 is about 10-11 months.

C.2.5. Length-Based Spawning Potential Ratio (LB-SPR)

The estimated SPR of R. kanagurta caught in the fishery in Ayungon and Bindoy is shown in Table 3. At present, SPR of the stock based on the 2 month monitoring data is 14.0% only. This is because the fishery is catching Table 3. Estimated spawning potential ratio of Rastrelliger kanagurta in Ayungon and Bindoy, Negros Oriental immature individuals, only 11% are above the

Lm50 (Fig. 13). To increase the SPR of R. Lc (cm SL) L50 (cm SL) Spawning Potential Ratio kanagurta to at least 20-32%, the L50 or 12.06 (actual) 14.86 14.0 % median of the projected size 13.07 15.96 21.0 % distribution of fish in the catches should 14.57 18.56 32.0% be set at 15.96-18.56cm SL. This means that catches smaller than this size range should be banned. SPR presented here is just for the 2 month monitoring period only. The study of Erisman et al. (2014) in California showed that SPR estimates increases with increasing spawning frequency. Hence, SPR of R. kanagurta in Negros may improve if monitoring will be conducted throught the spawning season (March through September) or even better for a year.

C.2.6. Harvest Control Reference Points

The estimated SPR for the species is below the target range of 20-30%, although increasing the median size of fish in the catches to 15.96-18.56cm SL would be more consistent with sustainability. Recruitment of R. kanagurta in various waters of the country peaks from June to August (compiled in Campos et al., 2013), so that spawning would be 1-2 months before.

Hence, resulting Lm50 is likely representative of the stock because the monitoring is within the known spawning period. In addition, Lm50 estimates is within the estimate of Olano et al (2007) in Lagonoy Gulf, Bicol. Based on the results of the study, the following are recommended:

• Establishing size limits of 15.96-18.56cm SL to increase the SPR of the species to 2032%. This will allow enough individuals to spawn before being caught.

• For gill nets targeting R. kanagurta, the mesh size should be increased to allow smaller/younger fish to pass through the net.

• Fish buyers should also be informed of the above recommendations. And it would be better if fish buyers will be instructed to buy R. kanagurta that are equal to or greater than the size limit only. By doing so, fishers will be discouraged in catching smaller individuals (no market for smaller individuals = no harvest of smaller individuals).

C.3. Sthenoteuthis oualaniensis (lumayagan)

C.3.1. General Biology

Sthenoteuthis oualaniensis or the purpleback flying squid (Family Ommastrephidae) usually occurs in tropical waters throughout the Indo-Pacific region from Okinawa in the north to northern Australia and from East Africa to the eastern central Pacific. Adults inhabits open waters over great depths of more than 200 to 400 m, while larvae and juveniles occur in clear, shallower water, including around coral reefs. The species preys primarily on small pelagic fishes and crustaceans (Carpenter & Niem, 2001).

There are 3 variants of purpleback flying squid based on size, dorsal photophore and gladius morphology. The dwarf form, the smallest, Figure 16. The target species Sthenoteuthis occurs in equatorial waters and is oualaniensis. characterized with the lack of dorsal mantle photophore patch and relatively smaller length at maturity (modal size 9-16cm ML of mature individuals). The middle-sized form on the other hand attains maturity at 12-19cm ML (modal size) with gladius having single or double lateral axes and occurs throughout the range of the species. While the giant variant, with single or double lateral latex also, occurs only in the northern Indian Ocean in the region of the Red Sea, Gulf of Aden and Arabian Sea, attains maturity at 40-50cm ML (modal size) and maximum size of 65cm ML. Between middle-sized and dwarf form, dwarf form exhibits higher growth rate, K = 3.65, (versus K = 2.38cm ML), and shorter lifespan, 302 days (versus 461 days) (Froese & Pauly, 2016; IUCN, 2016).

The reported maximum mantle length of the flying squid is 65cm ML, while the maximum published weight is 8.5kg. Spawning appears to be geographically widespread in continental slope waters and occurring year-round. Spawning takes place at night in the epipelagic zone, with the duration of the spawning season for individual females up to 1-3 months. After spawning once, females continue to feed and grow, while the next portion of oocytes matures and then spawning begins again. Each subsequent batch is quasi-equal in egg numbers. Egg masses are pelagic, and they float above the upper pycnocline layer. The species is caught by hook and line, hand jig and or mechanized jigs (Carpenter & Niem, 2001).

C.3.2. Size Distribution

A total of 937 squid individuals caught by squid hook and line were measured within the 2month monitoring period. The smallest individual caught measured 5 cm ML (size class 5.5cm), while the largest is 49 cm ML (size class 49.5cm) (Fig. 17). Approximately 55% of the total catch are below the estimated Lm50 (18.68cm ML, see Gonadal Maturation and

Maturation Curve section for explanation of Lm50). Estimates of length at first maturity (Lm50) by Mohamed et al. (2006) and Nair et al. (1990), 27.6 cm and 11.0 cm ML, respectively are 20 also indicated. The smaller Lm50 estimate of Nair et al. (1990) in Indian Ocean could be based on dwarf form squids.

C.3.3. Maturity Stages and Maturation Curve

A total of 22 S. oualaniensis individuals were examined for gonadal staging. The smallest size examined measured 13.5cm SL while 31.5cm SL was the n = 22 largest (Fig. 18). Out of 21 individuals, 16 were mature or 76% of the total biological samples with sizes ranging from 17.5 cm ML to 31.5 cm ML. The rest of the Mantle length (cm) samples were immature (5

Figure 18 . Gonadal maturation of Sthenoteuthis oualaniensis in individuals). S. Ayungon and Bindoy, Negros Oriental. Note: “ n ” above bars refer to oualaniensis spawn all the number of specimens examined per size class. year round.

Figure 19 shows the maturation curve or ogive of S. oualaniensis in Ayungon and Bindoy.

Based on the ogive, length at which 50% of the population matures (Lm50) is about 18.68cm

ML while Lm95 is at 22.78 cm ML. Compared to the estimate of Mohamed et al.,2006

(Lm50=27.6cm) estimate of the present study is lower, but is higher than the estimate of Nair et al., 1990

(Lm50=11.6cm). The lower estimate of Nair et al. (1990) in Indian Ocean could be again based on the dwarf form of S. oualaniensis. Note that

ogive and resulting Lm50 and Lm95 are dependent on the input length mature data, i.e. there are months when larger individuals caught are

larger in size which will result to larger Lm50 and months when catches are smaller in size

resulting to smaller Lm50. Hence, length at maturity estimates may improve if more samples were examined representing more size classes.

Based on the Lm50 estimate and distribution of the species, S. oualaniensis in Negros Oriental may be a medium size variant. This variant attains maturity at 12-19cm ML (modal size). C.3.4. Growth Curve

Figure20 shows the growth curve of S. oualaniensis which may be used in estimating the ages of mature specimens and or the age of individuals of any given length. Based on the growth curve, the corresponding relative age of the

estimated Lm50 (18.68cm ML) is about 7 months. This indicates that S. oualaniensis has to reach this age before they mature. Hence, catching them at smaller sizes will

prevent them from reaching their maturity. The corresponding age of Lm95 (22.78cm ML) on the other hand is about 10 months.

C.3.5. Length-Based Spawning Potential Ratio (LB-SPR)

The estimated SPR of S. oualaniensis in the fishery in Ayungon and Bindoy is shown in Table 4. At present, SPR of the stock based on the Table 4. Estimated spawning potential ratio of 2 month monitoring data is 20.0%. This is Sthenoteuthis oualaniensis in Ayungon and Bindoy, already within the recommended SPR Negros Oriental

value of 20-30%. To further sustain the fishery Lc (SL cm) L50 (SL cm) Spawning Potential of the flying squid, median length of the Ratio catches (L50) may be established at 21.64cm 9.81 (actual) 17.14 20.0 % ML. This will allow more individuals to grow 13.82 21.64 31.0 % and spawn before capture. 14.35 22.64 32.0 % C.3.6. Harvest Control Reference Points

The expensive price of the species is one of the limiting factor for the gonadal staging. Only 22 squid samples were examined which may have underrepresented the stock and in turn influenced the estimates of length at maturity.

Based on the results of the 2 month monitoring the following are recommended:

• Although the SPR (20%) of the flying squid fishery is within the recommended value, a size limit of 17.14cm ML is still recommended to further sustain the fishery.

• Fish buyers should also be informed of the above recommendation. And it would be better if fish buyers will be instructed to buy S. oualaniensis that are equal to or greater than the size limit only. By doing so, fishers will be discouraged in catching smaller individuals (no market for smaller individuals = no harvest of smaller individuals).

C.4. Thysanoteuthis rhombus (dalupapa)

C.4.1. General Biology

Thysanotheuthis rhombus is an epipelagic and oceanic species with a wide geographic distribution in tropical to subtropical waters. The species is commonly known as the Diamondback squid because of its large triangular shaped fins. They are capable of leaping out of the water but do not “fly” (glide) in the same manner as ommastrephids and Figure 21. The target species Thysanoteuthis rhombus onychoteuthids. The species occurs in near surface waters at night and mid-water depths by day. However, its vertical depth distribution can vary from region to region. Stomach content analysis of specimens (23cm ML) found that finfish and squid were both important component in their diet. Other organisms preyed upon by the squid included crustacean (IUCN, 2016).

The maximum reported length of T. rhombus is 100 cm ML, but is commonly caught to 60cm ML. The reported maximum weight on the other hand is 24 kg. The study of Miyahara et al. (2006) in the Sea of Japan using statolith growth increment counts suggest a lifespan of just a single year. T. rhombus is not an active swimmer during most of its life cycle, rather it propels itself slowly by gentle undulation of its long, broad diamond-shaped fins. Such low- energy lifestyle promotes very high growth rates, among the highest of all squids. In tropical Atlantic and southeastern Pacific, the squid may reach 80cm ML and 17.6 kg in just 300 days. For males, maturity is attained mainly at 40-55cm ML (age = 170-200days), while females mature at 55-65cm ML (age = 230-250 days) (Nigmatullin et al., 1995). Off Bonin Islands, all males larger than 70cm ML were mature and the smallest had a mantle length of just 55cm ML (Bower & Miyahara, 2005). For females, all squids larger than 74cm ML were mature. The study of Guerra et al. (2002) show that females can have very high potential fecundities of up to 4.8 million eggs, suggesting that spawning occurs intermittently in multiple batches.

According to Miyahara et al. (2006), spawning of the species is year-round in tropical waters, peaking in February-March.

T. rhombus is targeted by commercial fisheries in some regions of its range (e.g. Japan) at certain time of year. They can be caught using drifting, sometimes baited jigs and set nets. Catches appear to be consistent, suggesting that current levels are sustainable. However, further research is recommended in order to determine the precise distribution, population dynamics, life history and ecology, and potential threat processes affecting this species (IUCN, 2016; Froese & Pauly, 2016).

C.4.2. Size Distribution

A total of 470 squid individuals caught by squid hook and line were measured within the 2month monitoring period. The smallest individual caught measured 29 cm ML (size class 28.5cm), while the largest is 69 cm ML (size class 68.5cm) (Fig. 22). Of the catches, 98% are above the estimated Lm50 (see Gonadal Maturation and Maturation Curve section for explanation of Lm50). This indicates that most of the catch are mature and may have already spawned before capture.

Size Distribution Frequency of Thysanoteuthis rhombus (n=470) 20 Squid Hook and Line

15 L m50 =32.69cm ( this study) 10

0 28.5 30.5 32.5 34.5 36.5 38.5 40.5 42.5 44.5 46.5 48.5 50.5 52.5 54.5 56.5 58.5 60.5 62.5 64.5 66.5 68.5 Mantle Lenght (cm) Figure 22 . Size distribution frequency of Thysanoteuthis rhombus caught in Ayungon and Bindoy, Negros Oriental from May – July 2016. Note: L m50 is the size when 50% of the population mature.

C.4.3. Maturity Stages and Maturation Curve n = 10 Because of its expensive price, only 10 T. rhombus individuals were examined for gonadal staging. The smallest size examined measured 35.5cm ML while 65.5cm ML was the largest (Fig. 23). All examined specimens (100%) Mantle length (cm)

were in mature stage. It is not Figure 23 . Gonadal maturation of Thysanoteuthis rhombus in clear however, if the species Ayungon and Bind oy, Negros Oriental. Note: “ n ” above bars refer to the number of specimens examined per size class. matures at smaller sizes, as all specimens were mature. The study of Nigmatulin et al., (1995) in tropical Atlantic and southeastern Pacific showed that males attained maturity at 40-55cm ML, while females at 55-65cm ML. Apparently, T. rhombus in Negros Oriental matures at smaller sizes.

Figure 24 shows the maturation curve or ogive of T. rhombus in Ayungon and Bindoy. Based

on the ogive, length at which 50% of the population matures (Lm50) is about 32.69 cm ML

while Lm95 is at 47.09 cm ML. Compared to the results of previous studies, length at maturation of T. rhombus in Negros Oriental is relatively smaller. The studies of Nigmatullin et al. (1995) and Bower & Miyahara (2005) show that the species matures at 40cm ML and 55cm ML for male

and female, respectively. Note that ogive and resulting Lm50 and Lm95 are dependent on the input length mature data, i.e. there are months when larger individuals caught are larger in

size which will result to larger Lm50 and months when catches are smaller in size resulting to

smaller Lm50. Hence, length at maturity estimates may improve if more samples were examined representing more size classes.

Mantle length (cm)

Figure 24. Maturation curve of Thysanoteuthis rhombus in Ayungon and Bindoy, Negros Oriental.

C.4.4. Growth Curve

Figure 25 shows the growth curve of T. rhombus which may be used in estimating the ages of mature specimens and or the age of individuals of any given length. Based on the growth

results of Nagmatullin et al. (1995) (maturity at 5.7-8.3 months), age at maturation of the present study is very young. This result however need to be verified because the monitoring covered only 2 months.

C.4.5. Length-Based Spawning Potential Ratio (LB-SPR) The estimated SPR of T. rhombus in the Table 5. Estimated spawning potential ratio of Thysanoteuthis rhombus in Ayungon and Bindoy, Negros Oriental fishery in Ayungon and Bindoy is shown in

Table 5. At present, SPR of the stock based Lc (Sl cm) L50 (SL cm) Spawning Potential on the 2 month monitoring data is 14.0% Ratio only. Although most of the catches (98%) 61.99 (actual) 54.8 14.0 % were mature before capture, the 64.62 55.8 21.0 % SPR was low because the estimated Lm50 67.66 65.8 31.0 % is also low (32.69cm ML). The low Lm50 may have been interpreted by the SPR software that most of the stock are already caught. Perhaps, if the monitoring covered more months and more samples (including immature specimens) for gonadal examination, the Lm50 estimate may improve (closer to reported values), as well as the SPR. Basing from the 2 month actual data, SPR of T. rhombus can be increased to 21-31% by establishing size catch limits to 55.8- 68.8cm ML.

C.4.6. Harvest Control Reference Points

The expensive price of the species is one of the limiting factor for the gonadal staging. Only 10 squid samples were examined which may have underrepresented the stock and in turn influenced the estimates of length at maturity.

Based on the results of the 2 month monitoring the following are recommended:

• Size catch limit should be set to 55.8-65.8cm ML to increase the SPR to 21-31%. This will ensure sustainability of the species. • Fish buyers should also be informed of the above recommendation. And it would be better if fish buyers will be instructed to buy T. rhombus that are equal to or greater than the size limit only. By doing so, fishers will be discouraged in catching smaller individuals (no market for smaller individuals = no harvest of smaller individuals).

C.5. Caesio caerulaurea (dalagang bukid/sulig)

C.5.1. General Biology

Caesio caerulaurea (Family Caesionidae) inhabits coastal areas, primarily around coral reefs, to depths of around 40m. They feed by picking zooplankton. They are schooling, and often feed in large midwater Figure 26 . The target species Caesio caerulaurea aggregations; commonly forms schools together with Caesio varilineata, C. striata, and Pterocaesio tile. They are moderately important in coastal fisheries, and are common in markets in Indonesia and the Philippines. They can be caught by drive-in gill nets, surface gill nets, traps, trawls, spears and handlines. C. caerulaurea are marketed fresh and sometimes dried-salted. Juveniles are important as tuna baitfish in some areas. The maximum total length of this species is about 35cm, and is commonly caught up to 25cm (Carpenter & Niem, 2001).

C. caerulaurea sexually matures at 27cm (Lm50) or at about 14 months of age. With a lifespan of 4 to 4.5 years, a female may spawn three to four times (at least once a year) if it is not captured by fishers (Primavera, 1998).

C.5.2. Size Distribution

A total of 313 Caesio caerulaurea fish individuals caught by drift gill net c were measured within the 2-month L m50 =17.17 cm L m50 =15.58 cm monitoring period. The ( parallel study in ( this study) smallest individual caught measured Anrique 11.6 cm SL (size class 11.5cm) while the largest belongs to size class 19.5 cm SL (19 cm SL) (Fig. 27). 75% of the total catch were below the Lm50 (15.58 cm SL). Compared to the Figure 27. Size distribution frequency of Caesio caerulaurea result of a parallel study in Culasi, caught in Ayungon and Bindoy, Negros Oriental from May – Antique, the Lm50 of C. caerulaurea in July 2016. Note: L m50 is the size when 50% of the population Negros Oriental is smaller. mature. 27

C.5.3. Maturity Stages and Maturation Curve

A total of 37 Caesio caerulaurea individuals were examined for gonadal Gonad Staging of Caesio caerulaurea Gill Net (n=37) staging. The smallest size examined n = 4 11 8 8 6 100 % measured 15.5cm SL, while the largest 80 % is 20.5 cm SL (Fig. 28). Of the samples 60 % examined, 90% were mature (34 40 % individuals). Only 3 fish individuals 20 % were immature. The high proportion 0 % of mature individuals may be 15.50 16.50 17.50 18.50 19.50 attributed to the larger sizes of Immature Mature Standard Lenght (cm) examined samples (15.5-20.5cm SL), Figure 28 . Gonadal maturation of Caesio caerulaurea in which are within and above the Ayungon and Bindoy, Negros Oriental. Note: “ n ” above bars refer to the number of specimens examined per size estimated Lm50. unfortunately, no samples below the

Lm50 were obtained.

Based on the ogive, length at which 50% of the

population matures (Lm50) is about 15.58 cm SL while

Lm95 is at 15.79 cm SL. Compared to the Lm50 (17.18cm SL) estimate of C. caerulaurea in Antique (RARE

GDAHCRP, 2016), Lm50 in Negros Oriental is lower

(15.58cm SL). But note that ogive and resulting Lm50

and Lm95 are dependent on the input length mature data, i.e. there are months when larger individuals

caught are larger in size which will result to larger Lm50 and months when catches are smaller in size resulting

to smaller Lm50.

C.5.4. Growth curve

Figure 30 shows the growth curve of C. caerulaurea which may be used in estimating the ages of mature specimens and or the age of individuals of any given length. Based on the growth curve, the

relative ages of the estimated Lm50 (17.17 cm SL) and Lm95 (15.79cm SL) are 7 and 7.5 months. This indicates that C. caerulaurea has to reach this age before they mature. Hence, catching them at smaller sizes will prevent them from attaining maturity and, as a consequence, from contributing to the stock. The largest individual recorded (19.5cm SL) during the study was 20.5cm SL (Fig. 27), which is about 10 months relative age. This strongly suggests that the fishery is catching the stock before they reach 1 year old, and that the stock is made up mostly of young fish which do not live out their lifespan.

Lm50 = 15.58 cm @ 7 mos

Lm95 = 15.79 cm @ 7 .5 mos

Figure 30. Growth curve of Caesio caerulaurea in Ayungon and Bindoy, Negros Oriental. C.5.5. Length-Based Spawning Potential Ratio (LB-SPR)

The estimated SPR of C. caerulaurea Table 6. Estimated spawning potential ratio of Caesio caerulaurea in Ayungon and Bindoy, Negros Oriental caught in the fishery in Ayungon and Bindoy is shown in Table 6. At present, Lc (SL cm) L50 (SL cm) Spawning Potential Ratio SPR of the stock based on the 2 month 17.14 (actual) 14.09 1.0% monitoring data is 1.0% only. This is 24.72 22.09 21.0% because the fishery is catching immature individuals (75%). In 28.07 25.09 31.0% order to increase the spawning potential to the recommended value (20% and 30%) the

L50 or median length of the catches should be set at 22.09-25.09 cm SL. This means that catches smaller than 22.0cm SL should be banned. SPR presented here is just for the 2 month monitoring period only. The study of Erisman et al. (2014) in California showed that SPR estimates increases with increasing spawning frequency. Hence, SPR of C. caerulaurea in Negros may improve if monitoring will be conducted during the spawning season (January-March, Primavera, 1998). Monitoring during spawning season will allow collection of mature individuals in different size ranges.

C.5.6. Harvest Control Reference Points

Individuals caught in this study are relatively smaller and young, with 75% below the

estimated Lm50 of the species (15.58cm SL) and all were less than 1 year. Hence, resulting SPR is very low, 1% only and is well below the recommended SPR, 20-30%. To increase the SPR to

the recommended level, modal size limit of the catch (L50) maybe set to about 22.0925.09cm SL. This will allow more fish to grow and spawn before capture. Again, fish buyers should also be informed of the above recommendation. And it would be better if fish buyers will be instructed to buy C. caerulaurea that are equal to or greater than the size limit only. By doing so, fishers will be discouraged in catching smaller individuals (no market for smaller individuals = no harvest of smaller individuals).

C.6. Siganus fuscescens (danggit)

C.6.1. General Biology

Siganus fuscescens (Family Siganidae) is distributed in Indo-Malayan region from Andaman Islands eastward to NewCaledonia, north to the Ryukyu Islands, and south across the northern half of Australia; but extending to higher latitudes during summer, e.g. southern Honshu and southern New South Wales. The species can be found in shallow Figure 31. The target species Siganus fuscescens. coastal waters to depths of 50 m. Compared with the very similar Siganus fuscescens, it seems to prefer clear water. Siganus fuscescens is common on coral reefs, rock reefs and harbors. Fry arrive on coral reef flats in schools averaging to 200 individuals, but up to 5,000. By 3 months, average school size decreased to around 12. Adults feed on brown and green algae, while juveniles feed on filamentous algae and seagrasses. Spawning of the species is reported to occur in March-May and AugustOctober in Bolinao, Pangasinan, with sizes at first maturity estimated at 7.2cm SL for males and 8.8cm SL for females (Bellefleur, 1997, del Norte & Pauly 1990). In Pujada Bay, the spawning season of the species is from February-April and September-October (JumawanNanual & Metillo, 2008).

The species is of high importance to small-scale fishers, especially in areas with extensive seagrass beds. In Philippine market, they are sold as fresh, salted-dried or marinated. The species is caught by a variety of gears including seine nets, set nets, traps, gill nets and spears. Maximum total length about 40 cm, commonly to 25 cm (Froese & Pauly, 2016).

C.6.2. Size Distribution

A total of 907 Siganus fuscescens fish individuals were measured within the 2-month monitoring period. The smallest individual caught belongs to size class 4.5 cm SL while 16.5

proportion of smaller (=immature) individuals in the samples may be attributed to the monitoring period covered by the study which is in the tail end of the spawning season of the species (March-May) (Bellefleur, 1990; del Norte & Pauly, 1990; Jumawan-Nanual & Metillo, 2008). In addition, samples were caught by gill nets which are highly-selective, catching only those small fish enough to fit the net. Larger fish will bump into the net but are not readily caught.

C.6.3. Gonadal Maturation and Maturation Curve

Forty eight (48) specimens of S. fuscescens were examined for gonad maturation, with sizes ranging from 10.5-16.5cm SL (Fig. 33). Of these, 18 individuals (37.5%) were in mature and spent stages. The smallest mature specimen measured 10.5cm SL. It is not

clear, however, if S. Figure 33 . Gonadal maturation of Siganus fuscescens in fuscescens starts to mature at this Ayungon and Bindoy, Negros Oriental. Note: “ n ” above bars length, because the refer to the number of specimens examined per size class. smallest mature specimen examined was also 10.5cm SL. It is hence possible that fish smaller than this size had already spawned and were in the redeveloping stage at the time of the study. Smaller mature individuals of this species have been reported in other areas of the country. For example, de la Paz & Aragones (1988) showed that S. fuscescens in Bolinao, Pangasinan can mature at a size as small as 5.6cmSL. In the same are, they are mature at 7.2cm SL (male) and 8.8cm SL (females) (Bellefleur, 1990). Again, the relatively lower proportion of mature individuals in the samples may be attributed to the monitoring period covered by the study which is in the tail end of the spawning season of the species (March-May) (Bellefleur, 1990; del Norte & Pauly, 1990; Jumawan-Nanual & Metillo, 2008).

Based on the ogive, length at which 50% of the population

matures (Lm50) is about 14.39 cm SL. This estimate is almost 2x larger than the estimates of Bellefleur (1990), 7.2cm SL for L m50=14.39 cm L m95=16.44 cm males and 8.8cm SL for females). Lm95 on the other hand is estimated at 16.44 cm SL. But note that ogive and resulting

Lm50 and Lm95 are dependent on the input length mature data, i.e. there are months when larger individuals caught are

larger in size which will result to larger Lm50 and months when

catches are smaller in size resulting to smaller Lm50. Hence, resulting estimates may improve if the monitoring covered Figure 34 . Maturation curve of Siganus fuscescens in Ayungon the spawning seasons of the species, when relatively larger and Bindoy, Negros Oriental. mature individuals are usually observed.

C.6.4. Growth Curve

(14.39cm SL) of S. fuscescens in Negros Oriental is about 11 months, while the smallest mature (10.5cm SL) specimen had a corresponding age of 8 months. Compared to the results of Bellefleur (1990) (smallest mature = 2.3-3.9 months), the age of the smallest mature individual (8 months) observed in this study is older. Again, these estimates are based only on the examined samples.

C.6.5. Length-Based Spawning Potential Ratio (LB-SPR)

The estimated SPR of S. fuscescens caught in the fishery in Ayungon and Bindoy is shown in Table 7. At present, SPR of the stock based on the 2 month monitoring data is 2.0% only. This is because the fishery is catching Table 7. Estimated spawning potential ratio of Siganus immature individuals (98%). In order to fuscescens in Ayungon and Bindoy, Negros Oriental increase the spawning potential to the

Lc (SL cm) L50 (SL cm) Spawning Potential Ratio recommended value (20% and 30%) the L50 5.72 (actual) 7.44 2.0% or median length of the catch should be set 11.20 13.04 22.0% at 13.04-14.44cm SL. This means that 12.66 14.44 32.0% catches smaller than 13.04cm SL

should be banned. Note that SPR presented here is just for the 2 month monitoring period only. Resulting estimates may improve if the monitoring covered the spawning seasons of the species, when relatively larger mature individuals are usually observed in number.

C.6.6. Harvest Control Recommendations

Based on the results of the 2 month monitoring the following are recommended:

• For gill nets targeting S. fuscescens, the mesh size should be increased to allow smaller/younger fish to pass through the net. Based on the results of this study, size limit should be set between 13.04cm SL and 14.4cm SL. This will allow enough individuals to spawn before capture and increase the SPR of the stock to 20%-30%. • Fish buyers should also be informed of the above recommendations. And it would be better if fish buyers will be instructed to buy S. fuscescens that are equal to or greater than the size limit only. By doing so, fishers will be discouraged in catching smaller individuals (no market for smaller individuals = no harvest of smaller individuals).

C.7. Dussumieria elopsoides (manodlong)

C.7.1. General Biology

Dussumieria elopsoides or the slender rainbow sardine (Family Clupeidae) is a pelagic inshore species, which closely resembles and often misidenified as D. acuta. They Figure 36. The target species are distributed in the Indo-Pacific from Suez and western Dussumieria elopsoides. Indian Ocean (Persian Gulf to Mombasa, possibly Madagascar) to India, Indonesia, Malaysia, and Thailand; northward to China and eastward to Caroline and Marshall Islands and perhaps also in Solomon islands.

In the Philippines, D. elopsoides contributes to the cacthes of the family Clupeidae (sardines) which has significant contribution to both municipal and commercial sectors of the fishery. The species are caught by ringnets and dip nets. Catches of the species are marketed fresh, dried and or salted. If allowed to grow, the D. elopsoides can grow up to 20cm SL (Froese & Pauy, 2016).

C.7.2. Size Distribution

Fifty eight (58) Dussumieria elopsoides fish individuals caught by beach seine were measured within the 2-month L m50 =10.75 cm ( this study ) monitoring period. The smallest individual caught measured 7.4cm SL (size class 7.5cm), while 14.2cm (size class 14.5cm) was the largest (Fig. 37). Of the catches, 54% were below the estimated Figure 37 . Size distribution frequency of Dussumieria elopsoides caught in Ayungon and Bindoy, Negros Lm50 (10.75cm SL, see Gonadal Oriental from May – July 2016. Note: L m50 is the size when Maturation and Maturation Curve 50 % of the population mature section for explanation of Lm50). This indicates that half of the D. elopsoides catch were immature. Modal length for this species

belongs to size class 8.5-9.5 cm SL.

C.7.3. Gonadal Maturation and Maturation Curve

A total of 58 D. elopsoides individuals were examined for gonadal staging, with size ranging from 7.5c - 14.5cm SL (Fig. 38a). Of the samples, only 4 individuals were mature (7%) with corresponding sizes of 12.5 - 14.5cm SL. The rest of the samples were immature. The low proportion of mature samples may be attributed to the monitoring months covered (AprilJune) which is outside the spawning season of most sardines species (August-March). In addition, the species is probably just a bycatch (=not targeted) of beach seine.

Based on the constructed ogive (Fig. 38b) length at which 50% of the population matures

(Lm50) is about 10.75 cm SL while Lm95 is at 11.65 cm SL. But note that ogive and resulting Lm50

34 and Lm95 are dependent on the input length mature data, i.e. there are months when larger individuals caught are larger in size which will result to larger Lm50 and months when catches are smaller in size resulting to smaller Lm50. Hence, resulting length at maturity estimates may improve if monitoring covered the spawning seasons of sardines and if more samples were obtained from different gears.

C.7.4. Growth Curve

Figure 39 shows the growth curve of D. elopsoides which may be used in estimating the ages of mature specimens and or the age of individuals of any given length. The corresponding ages of the catches (7.5-14.5cm SL) is from 10-24 months, with most at the age of 11-12.5 months (8.5-9.5cm SL). Based on the growth curve, the corresponding age of the estimated

Lm50 (10.75cm SL) in this study is 15 months, while Lm95 (11.65cm SL) showed a corresponding age of about 17 months. Again, these estimates are based only on the examined samples.

Lm50 = 10.75 cm @ ̴ 15 mos

Lm95 = 11.65 cm @ ̴ 17 mos

Figure 39. Growth curve of Dussumieria elopsoides in Ayungon and Bindoy, Negros Oriental. C.7.5. Length-Based Spawning Potential Ratio (LB-SPR)

The estimated SPR of D. elopsoides caught in the fishery in Ayungon and Bindoy is shown in Table 8. At present, SPR of the stock based on the 2 month monitoring data is 3.0% only. This

Table 8. Estimated spawning potential ratio of Dussumieria is because the fishery is catching elopssoides in Ayungon and Bindoy, Negros Oriental immature individuals (56%). To increase the SPR of D. elopsoides

Lc (SL cm) L50 (SL cm) Spawning Potential to at least 20% and 30%, the L50 or median Ratio length of the catches should be set at 10.9cm 8.03 (actual) 8.38 3.0 % SL and 112.0cm SL, respectively. This means 10.73 10.9 21% that catches smaller than this size should be 11.14 12.0 30% banned. SPR presented here is just for the 2 month monitoring period only and is based only on the catches of beach seine.

C.7.6. Harvest Control Reference Points

• The estimated SPR of the species is 3.0% only and is below the recommended SPR range. The median size limit should be set to 10.9-12.0cm SL to attain a spawning potential ratio of 20-30% to ensure sustainability of the stock.

• Beach seines typically catch young individuals below Lm50. During the study, small rainbow sardine made up about 56% of beach seine catches. Prohibiting the catching of juveniles will allow a larger portion of the stock to grow to maturity and contribute to the stock. Hence, establishment of closed season for beach seine operation is suggested. This will benefit not only the rainbow sardine, but all those species whose juveniles are routinely caught by the gear. This however needs more detailed information before establishment (e.g. what month to close and how many months).

C.8. Herklotsichthys quadrimaculatus (tamban)

C.8.1. General Biology

Herklotsichthys quadrimaculatus or the Bluestripe herring (Family Clupeidae) can be found in Indo-West Pacific from entire eastern coast of Africa, Madagascar, Mauritius eastward to Japan, including Indonesia, eastern Australia, south to New Caledonia, and F igure 40. The target species Herklotsichthys quadrimaculatus eastward to Samoa. This species is classified as coastal, pelagic and forms dense schools during daytime along the shoreline and among reefs in a few metres of water. They usually feed on zooplankton, juvenile stage copepods, but larger prey as adults (chaetognaths, polychaetes, shrimps, and small fishes, phytoplankton. The species is relatively fast-growing and short-lived. They are multiple spawner in which 20% of their populations spawns during each month (1,700-3,200 eggs/spawning: 283-354 eggs/g). It’s maximum length is reported to be 14 cm and commonly between 8-10cm. They attain maturity and spawn within their first year and probably survive only a few months after maturity (Froese & Pauly, 2016).

C.8.2.Size Distribution

A total of 797 Herklotsichthys quadrimaculatus fish individuals were measured within the 2month monitoring period. The smallest individual caught measured 7.3 cm SL (size class 7.5cm), while 15 cm SL (size class 15.5cm) was the largest (Fig. 41). Approximately 75% of

the catches were below the estimated Lm50 (10.53cm SL, see Gonadal Maturation and

Maturation Curve section for explanation of Lm50). This indicates that H. quadrimaculatus are mostly immature when caught. Modal length for this species belongs to size class 9.5 cm SL.

L m50 = 10.4 cm ( parallel study Antique) L m50 = 10.53 cm ( this study)

Figure 41 . Size distribution frequency of Herklotsichthys qudrim aculatus caught in Ayungon and Bindoy, Negros Oriental from May – July 2016. Note: L m50 is the size when 50% of the population mature.

C.8.3. Gonadal Maturity and Curve

A total of 311 H. quadrimaculatus individuals were examined for gonadal staging. The smallest size examined measured 7.5cm SL and the largest is 12.5 cm SL (Fig. 42a). Of the samples, 211 (67%) were immature and 32% (100 individuals) were in mature and spent stage. Mature individuals were first observed in size class 9.5 cm SL.

Based on the ogive, length at which 50% of the population matures (Lm50) is about 10.53 cm

SL while Lm95 is at 11.5 cm SL. These estimates are comparable to the results of a parallel study conducted in Antique on the same species (Lm50 = 10.4cm SL, Lm95 = 11.4cm SL), so are likely accurate.

C.8.4. Growth Curve

The corresponding ages of the catches (7.5-14.5cm SL) is from 7-35 months, with most being about 12 months (19.5cm SL). According to Lavapie-Gonzales et al. (1997), H. quadrimaculatus can reach a length of 16.5cm SL. This indicates that H. quadrimaculatus are able to grow their lifespan.

Based on the growth curve (Fig. 43), the corresponding age of the estimated Lm50 (10.53cm SL) in this study is just over 14months, while the smallest mature (9.5cm) individual showed a corresponding age of about 12 months. This suggests that H. quadrimaculatus has to reach this age before they mature. Again, these estimates are based only on the examined samples.

C.8.5. Length-Based Spawning Potential Ratio (LB-SPR)

Table 9. Estimated spawning potential ratio of Herklotsichthys The estimated SPR of H. quadrimacuatus quadrimaculatus in Ayungon and Bindoy, Negros Oriental caught in the fishery in Ayungon and Bindoy is

Lc (SL cm) L50 (SL Spawning Potential Ratio shown in Table 9. At present, SPR of the cm) stock based on the 2 month monitoring 8.10 (actual) 9.36 59.0 % data is 59%. This is well above the recommended value (20-30%). This may indicate that the bluestripe herring fishery in Negros Oriental is at sustainable level. But note that SPR presented here is just for the 2 month monitoring period only.

C.8.6. Harvest Control Reference Points

Based on the results of the 2 month monitoring the following are recommended:

• Actual SPR value of the catches (59%) is well above the recommended value (20-30%). To further sustain the fishery, modal size of the catches may be set at 9.36cm SL.

• Fish buyers should also be informed of the above recommendation. And it would be better if fish buyers will be instructed to buy H. quadrimaculatus that are equal to or greater than the size limit only. By doing so, fishers will be discouraged in catching smaller individuals (no market for smaller individuals = no harvest of smaller individuals).

C.9. Encrasicholina heteroloba (bolinao)

C.9.1. General Biology

Encrasicholina heteroloba or the shorthead anchovy (Family Engraulidae) is a marine, pelagic, schooling inshore species. It is widely distributed in the Indo-Pacific from Red Sea, East Africa to at least northern Madagascar, eastward to Bay of Bengal, Gulf of Thailand, and Indonesia; northward to southern Japan; southward to Cape York, Queensland, also Palau, Caroline Islands to Figure 44. The target species Kosrae, and eastward to Samoa. Encrasicholina heteroloba.

The shorthead anchovy is a short-lived species with a lifespan of less than a year. It feeds mainly on planktonic crustacean such as copepods. When allowed to grow, it can reach up to 12.0cm SL. Females usually mature at 4.3-8.5cm TL. During spawning (year-round with peak in July), females are capable of releasing 100-2,400 eggs every 2 days.

E. heteroloba is relatively important in coastal fisheries. Catches are marketed fresh, dried, dried-salted or made into fish meal, fish sauce, or fish balls. They can be caught mainly with purse seines, beach seines, and fish traps often using light and sometimes with bottom trawls (Froese & Pauly, 2016)..

C.9.2. Size Distribution

A total of 277 Encrasicholina heteroloba caught by beach seine were measured within the 2month monitoring period. The smallest individual caught measured 2.5cm SL (size class 1.5cm) while the largest measured 9.8cm SL (size class 8.5cm SL) (Fig. 45). Of the catches, 52% were above the

Lm50 (6.68cm SL). Modal length of the catches belongs to size class 6.5cm SL.

C.9.3. Gonadal Maturation and Maturation Curve

A total of 227 Encrasicholina heteroloba individuals were examined for gonadal staging. The smallest size examined measured 2.5cm SL while the largest is 9.5 cm SL (Fig. 46). Out of 227 individuals, 130 were mature or 50% of the Figure 46 . Gonadal maturation of Encrasicholina total samples. The remaining heteroloba in Ayungon and Bindoy, Negros Oriental. Note: “ n ” above bars refer to the number of specimens examined 97 were staged as immature. According to Yakoh et al. (2008), spawning of the species is

year-round with a peak around July. The monitoring started in July and is within the peak spawning season, hence, relatively higher number of mature individuals were sampled.

Based on the ogive, length at which 50% of the

population matures (Lm50) is about 6.68cm SL. This is comparable to the estimates of Yakoh et al. L m50=6.68 c (2008) in Thailand, 6.09cm SL for male and 6.44cm m SL for female, and hence are probably accurate.

Lm95 on the other hand is estimated at 8.89cm SL

But note that ogive and resulting Lm50 and Lm95 are dependent on the input length mature data, i.e. there are months when larger individuals caught

are larger in size which will result to larger Lm50 and Figure 47 . Maturation curve of Encrasicholina months when catches are smaller in size resulting heteroloba in Ayungon and Bindoy, Negros Oriental. to smaller Lm50 .

C.9.4. Growth Curve

The corresponding ages of the catches (2.5-9.5cm SL) is from 1.5-9.0 months, with most being about 4-5 months (6.57.5cm SL). According to FishBase, E. heteroloba can reach a length of 20.0cm SL in a year. This indicates that E. heteroloba are able to grow their lifespan. Based on the growth curve (Fig. 48), the corresponding age of the estimated

Lm50 (6.68cm SL) is 4.5 months, while the smallest mature (5.5cm) individual showed a corresponding age of about 3.5 months. This indicates that E. heteroloba is a short-lived species.

C.9.5. Length-Based Spawning Potential Ratio (LB-SPR)

Table 10 shows the spawning potential ratio of E. heteroloba caught by beach seine in

Table 10. Estimated spawning potential ratio of Encrasicholina Ayungon and Negros. At present, the SPR heteroloba in Ayungon and Bindoy, Negros Oriental of the stock is 54%. This percentage is well above

Lc (cm) L50 (cm) Spawning Potential Ratio the recommended SPR value of 20% and 7.38 (actual) 6.61 54% 30%.

C.9.6. Harvest Control Reference Points

• The estimated SPR of the species (54%) is well above the recommended level (2030%), indicating that the fishery of E. heteroloba in Negros Oriental is still sustainable.

• Beach seine typically catches smaller individuals because of its small mesh size. While E. heteroloba, relatively smaller than other fish is not affected by the small mesh size, other fish species may be affected. Hence, establishment of closed season for beach seine operation is suggested. This will benefit all those species whose juveniles are routinely caught by the gear. This however needs more detailed information before establishment (e.g. what month to close and how many months).

C.10. Encrasicholina punctifer (bolinao)

C.10.1. General Biology

Encrasicholina punctifer or the Buccaneer anchovy (Family Engraulidae) is a marine, pelagic, schooling inshore and oceanic species. It is widely distributed in the Indo-Pacific from the Persian Gulf and Red Sea south to perhaps Durban, but not Madagascar, Figure 49 . The target species Encrasicholina punctifer. to India, probably also Myanmar; Gulf of Thailand, Indonesia, northern Australia to at least Brisbane in the east, and as far eastward as Tahiti; also known from the Philippines, southern Japan, and eastward to at least 155°W longitude, and Hawaii.

E. punctifer is relatively important in coastal fisheries. In the Philippines, E. punctifer is said to comprise up to 22% of Stolephorus catches, and probably makes significant contribution elsewhere in its wide range. The species is caught mainly by purse seines, beach seines, and bamboo-stake traps, often using light, and sometimes in bottom trawls. Catches are marketed fresh, dried, dried-salted or made into fish meal, fish sauce, or fish balls.

Spawning season of the species is year-round, with a peak in September-March. Length at which the females mature is at 6.19-6.47cm SL (Yakoh et al., 2008). When allowed to grow, it can reach up to 13.0cm TL (=10.8cm SL) (Froes & Pauly, 2016).

C.10.2. Size Distribution

A total of 100 Encrasicholina heteroloba caught by beach seine were measured within the 2month monitoring period. The smallest individual caught measured 6cm SL while 9cm SL

was the largest (Fig. 50). All samples were above the Lm50 (5.91cm SL). Estimates of Lm50 from other studies are also indicated for comparison. Modal length of the catches is 7.5cm SL.

Size Distribution of Encrasicholina punctifer (n=100) 100 L m50 =5.75 cm Beach Seine ( Maack & George, 1999) 80 L m50 = 5.91 cm ( this study) 60 L m50 =6.19 cm (M) & 6.47cm (F ) 40 ( Yakoh et al., 2008)

0 5.5 6.5 7.5 8.5 9.5 Standard Lenght (cm)

Figure 50 . Size distribution frequency of Encrasicholina punctifer caught in Ayungon and Bindoy, Negros Oriental from May – July 2016. Note: L m50 is the size when 50% of the population mature.

C.10.3. Gonadal Maturation and Maturation Curve

All one hundred (100) E. heteroloba examined for gonadal staging were mature (Fig. 51a). According to Yakoh et al. (2008) and Maack & George, 1999), spawning of the species is yearround, although peak activity is observed in January and during southwest monsoon.

Based on the ogive, length at which 50% of the population matures (Lm50) is about 5.91 cm SL. This estimate is comparable to the estimate of Maack & Georger (1999), 5.75cm SL, but is lower than the estimates of Yakoh et al. (2008), 6.19cm SL for male and 6.47cm SL for females.

Lm95 on the other hand is estimated at 6.29cm SL.

C.10.4. Growth Curve

The corresponding ages of the catches (6.5-9.5cm SL) is from 7-18.0 months, with most being about 12 months (8.5cm SL). Based on the growth curve

(Fig. 52), the corresponding age of the Lm50 = 5.91cm @ 7 mos

estimated Lm50 (5.94cm SL) is 7.0 Lm95 = 6.29 cm @ 8.5 mos months, while the Lm95 (6.29cm SL) showed a corresponding age of about 8.5 months. Figure 52 . Growth curve of Encrasicholina punctifer in Ayungon and Bindoy, Negros Oriental.

C.10.5. Length-Based Spawning Potential Ratio (LB-SPR) Table 11. Estimated spawning potential ratio of

Encrasicholina The spawning potential ratio of E. punctifer in Ayungon and Bindoy, Negros Oriental. punctifer caught by beach seine in

Lc (cm) L50 (cm) Spawning Potential Ayungon and Bindoy, Negros Oriental is Ratio 63%. This is already 7.04 (actual) 7.61 63% above the recommended SPR value, which 20-30%.

C.10.6. Harvest Control Reference Points

• The estimated SPR of the species (63%) is well above the recommended level (2030%), indicating that the fishery of E. punctifer in Negros Oriental is still sustainable. • Beach seine typically catches smaller individuals because of its small mesh size. While E. punctifer, relatively smaller than other fish is not affected by the small mesh size, other fish species may be affected. Hence, establishment of closed season for beach seine operation is suggested. This will benefit all those species whose juveniles are routinely caught by the gear. This however needs more detailed information before establishment (e.g. what month to close and how many months).

C.11. Catch and Effort Monitoring

The information on catch and effort recorded by hired enumerators in the monitored barangays allows computation of catch rates, which is a more reliable index of stock abundance than fisheries landings. Other information than can be gleaned from the catch and effort records are total harvest of the gears in the barangays monitored, species composition, and fishing ground information (where fishers operate). Records on specific areas fished by each trip also provide valuable insights on the behavior and distribution of the target species.

C.11.1. Catch of Monitored Gears

The total catch of the monitored fishing gears in the monitored brgys during the 2 month period is presented in Table 12. These include all species caught. Of the total catch (20, 991.28kg), target species contributed 58% (12,174.94 kg) with S. crumenophthalmus and T. rhombus contributing the highest, 16% or 3,321kg and 12.3% or 2,700.3kg, respectively (Fig. 53). Among the target groups, giant squids (T. rhombus and S. oualaniensis) showed the highest contribution, 23% (4,800kg). This was followed by sardines (sardines, Clupeidae mostly Spratelloides, H. quadrimaculatus, S. lemuru, A. sirm) at 3,358.6kg or 16% and Engraulidae (2.2% or 466.5kg).

Among barangays, high catch was recorded in Tinaogan (8,466.87 kg or 64.4%), while the lowest was in Iniban (457.40 kg or 9.6%) (Table 12). Record of catches however was dependent on the number of trips recorded by the enumerator, and hence, may not well represent the total catches of the fishing gears in the brgys.

Table 12. Total catch of the monitored gears in the monitored brgys in Ayungon and Bindoy, Negros Oriental from May-July 2016. Total Catch (kg) Gear Iniban Awaan Tampocon I Anibong Tinaogan Domolog Cabugan Malaga Fish Corral 0.0 0.0 0.0 0.0 629.5 31.0 0.0 0.0 Beach Seine 0.0 0.0 0.0 2,008.6 0.0 0.0 0.0 0.0 Hook&Line 37.0 1,506.5 1,051.5 80.3 437.4 338.9 1,693.5 1,900.1 Jigger 126.1 0.0 0.0 0.0 0.0 0.0 0.0 1,320.2 Jigger(for giant squids) 0 0 0.0 0 0 0.0 0 162.85 Drift Gill Net 0 0 0 0 1163.85 371.25 0 0 Spear 0 0 0 76.75 0 0 0 0 Gill Net 294.35 13 534 452.9 6236.1 279.8 0 232 Scoop Net 0 0 0 0 0 13.9 0 0

457.40 1,519.51 1,585.50 2,618.50 8,466.87 1,034.85 1,693.50 3,615.15 20,991.28

Figure 53. Overall species composition of the monitored fishing gears in 8 brgys (Ayungon: Brgys. Iniban, Awaan, Tampocon II, Anibong; Bindoy: Domolog, Tinaogan, Cabugan, Malaga in Negros Oriental rom May- July 2016.

Fish Corral Beach Seine Bottom Set Gill Net

Hook and Line Jigger (for giant squids) Jigger Spear

Drift Gill Net Scoop Net

Figure 54 . Species composition of Fish Corral, Beach Seine, Hook and Line, Jigger, Jigger (for giant squids), Drift Gill Net, Spear, Gill Net and Spear in Negros Oriental from May -July 2016.

A detailed examination of the species composition of catches by gear type is presented in Fig. 54. Among the gears, hook and line and bottom set gill net caught considerable volume of S. crumenophthalmus (16-39%), while sardines were, mainly caught by drift gill net and bottom set gill net. Giant squids on the other hand were caught mostly by jiggers and hook and line. Between gears, catches of beach seines and scoop nets were dominated by smaller-sized fish (e.g. sardines - Clupeidae and anchovies – Engraulidae), while catches of fish corrals, gill nets, spear and hook and line were mostly larger in size. Again, these results however are based on the 2 month data only.

C.11.2. Catch Rates and Effort Catch rates are indicative of catch efficiencies of the various fishing gears as well as stock abundance. In this report catch rates are expressed as kg per fisher per trip. Fishing effort is expressed as number of fishers per gear type, which was derived by multiplying the number of fishers per operation by the number of gear unit. Fishing frequency, on the other hand, refers to the number of fishing days per month and the seasonality of fishing activities, if any.

Mean catch rates and fishing Table 13. Catch rates and fishing effort of Beach Seine, Drift Gill effort of the gears monitored Net, Fish Corral, Gill Net, Hook and Line, Jigger, Jigger (for giant squids), Scoop Net, Spear in Ayungon and Bindoy, Negros Oriental based on the present study is based on the results of the 2 month monitoring. presented in Table 13. Number of fishers operating No. of fisher Catch Rates Effort (no. (kg/fishers/trip) of each gear is also Gear hours/trip) indicated. Based 49 1.6 on the data, Beach 14 3.2 8.4 highest catch rate Seine 4 3.9 3.6 150 was recorded by Drift Gill 2.2 2.1 Net 3.8 jigger (mean 5.7, Fish Corral range 4.8-6.7 Bottom kg/fisher/trip), Set Gill while scoop net Net recorded the lowest (mean 0.6 Hook and Line 156 3.9 5.6 kg/fisher/trip). High catch rate of Jigger 48 5.7 4.4 jigger is mainly attributed to its Jigger (for giant squids) 18 1.8 6.0 Scoop Net Spear 17 0.6 3.3 targets species rather than effort. 30 5.4 4.7 The giant squids are relatively Mean larger in size and weigh at least a Total no. of fisher 3.16 4.65 kilogram each. Lower 486 catch rate of scoop net on the other hand is attributed to the nature of its operation which relies heavily on the appearance of schooling or aggregating fish. In addition, scoop net operates only later in the monitoring due to its seasonal target (anchovies). The results of the 2 month monitoring showed that catch rate is not always a function of fishing effort, but rather of the target species.

C.11.3. Extrapolation of Total Catch

Total catch of the fishing gears monitored were extrapolated to project catches for one year. The purpose of the extrapolation is to estimate the production of the monitored gears in each of the barangays as an indicator of the potential supply to markets. But note that this extrapolation may underestimate the total catch because the basis for extrapolation covered only 2 months and was outside the spawning season of some target species. During spawning months, catches of gears are usually high.

Total catch of each gear was extrapolated by multiplying the catch rate (average kg/fisher/trip) with mean number of fishing days per month, number of fishing months per

Table 14. Catch matrix showing the estimated annual catch of target gears in brgys. Iniban, Awa-an, Tampocon II, Anibong, Domolog, Tinogan, Cabugan and Malaga (a) and summary of the estimated annual catch by gear and by brgy. (b)

No. of No. fishing Catch Rates Effort (no. of Est. Annual a Municipality Brgy Gear Fishers days/mo (kg/fishers/trip) hours/trip) Catch (MT)

Beach Seine Ayungon Anibong 49 14.7 1.6 8.4 13.8 13.8 Drift Gill net Bindoy Domolog 2 20.0 1.0 3.5 0.5 15.3 Bindoy Tinaogan 12 19.0 5.4 3.6 14.8 Fish Corral Bindoy Domolog 2 1.0 4.5 3.3 0.1 1.6 Bindoy Tinaogan 2 19.7 3.2 1.0 1.5 Bottom Set Gill net Ayungon Tampocon II 48 8.3 3.5 6.0 16.7 41.7 Ayungon Awaan 16 1.0 6.5 5.5 1.2 Ayungon Iniban 14 10.0 1.1 3.4 1.8 Ayungon Anibong 17 16.0 1.2 2.1 3.9 Bindoy Malaga 6 13.0 1.8 2.8 1.7 Bindoy Domolog 28 19.0 0.5 2.6 3.2 Bindoy Tinaogan 48 20.7 1.1 4.4 13.1 Hook & Line Ayungon Tampocon II 20 12.7 4.9 2.0 14.9 99.4 Ayungon Awaan 20 15.7 5.4 6.5 20.3 Ayungon Iniban 6 2.3 4.1 1.7 0.7 Ayungon Anibong 10 8.3 1.2 8.1 1.2 Bindoy Cabugan 24 20.3 4.4 4.2 25.7 Bindoy Malaga 21 15.3 5.7 6.8 22.0 Bindoy Domolog 28 20.0 1.8 3.2 12.1 Bindoy Tinaogan 6 16.7 2.0 3.1 2.4 Jigger Ayungon Malaga 5 7.3 6.7 2.6 2.9 47.5 Bindoy Iniban 43 18.0 4.8 6.3 44.6 Jigger (for giant squids) Bindoy Malaga 18 10.7 1.8 6.0 4.2 4.2 Scoop Net Bindoy Domolog 17 1.5 0.6 3.3 0.2 0.2 Spear Ayungon Anibong 30 3.3 5.4 4.7 6.4 6.4 230.1 230.1

b T otal Catch (MT) Gear Iniban Awaan Tampocon II Anibong Tinaogan Domolog Cabugan Malaga TOTAL

Fish Corral 0.0 0.0 0.0 0.0 1.5 0.1 0.0 0.0 1.6 Beach Seine 0.0 0.0 0.0 13.8 0.0 0.0 0.0 0.0 13.8 Hook&Line 0.7 20.3 14.9 1.2 2.4 12.1 25.7 22.0 99.4 Jigger 44.6 0.0 0.0 0.0 0.0 0.0 0.0 2.9 47.5 Jigger(for giant squids) 0 0 0.0 0 0 0.0 0 4.2 4.2 Drift Gill Net 0 0 0 0 14.8 0.5 0 0 15.3 Spear 0 0 0 6.4 0 0 0 0 6.4 Bottom Set Gill Net 1.8 1.2 16.7 3.9 13.1 3.2 0 1.7 41.7 0 0 0 0 0 Scoop Net 0.2 0 0 0.2 47.11 21.60 31.67 25.36 31.79 16.10 25.70 30.80 230.1 230.1 year (assumed to be 12 months) and number of fishers using the gear type. The results of the extrapolation is presented in Tables 14a and 14b. The estimated annual catch of the target gears is 230.1 MT. Among the gears presented, hook & line contributed the highest (99.4 MT or 43.2%), probably because a lot of fishers are using them (135) and their catch rates are higher (1.8-5.7kg/fisher/trip). This was followed by jigger (20.7% or 47.5 MT) and bottom set gill net (18.1% or 41.7%). Between barangays, Iniban (Ayungon) showed the highest catch (47.11 MT or 20.5%), where catch of jigger targeting giant squids is also the highest. The barangay with the least contribution is Domolog (7% or 16.1 MT).

It can be seen from Table 14a that the number of fishing days per month were substantially variable ranging from 1-20.7 days/month. This values are used in the extrapolation and hence, resulting extrapolated values may be underestimated. In most fishing ground grounds, fishing days range from 15-20 days.

The composition of the extrapolated catch is shown in Table 15. For target S. crumenophthalmus, contribution to annual catch is about 32.0% (71.84MT) while the two giant squids (S. oualaniensis and T. rhombus) contributed 21.39% (48.03 MT) and 10.46% (23.49 MT), respectively. All sardines (Clupeidae) on the other hand contributed 16.69% (37.48MT) with H. quadrimaculatus as the most dominant (7.1% or 16.0MT). For the nontarget groups, Lethrinidae showed the highest contribution (8.92MT or 3.97%).

Table 15. Composition of estimated annual catch in brgys. Iniban, Awa-an, Tampocon II, Anibong, Domolog, Tinogan, Cabugan and Malaga in Negros Oriental. Italicized taxa are the target species. Taxa Total Catch (MT) Iniban Awaan Tampocon II Anibong Tinaogan Domolog Cabugan Malaga Total % contn Selar crumenophthalmus 1.25 0.13 10.15 0.13 5.30 0.00 14.37 40.52 71.84 32.00 Sthenoteuthis oualaniensis 1.17 2.67 4.56 0.00 0.00 0.00 9.87 29.77 48.03 21.39 Thysanoteuthis rhombus 0.33 18.89 0.00 0.00 0.00 0.00 0.61 3.66 23.49 10.46 Herklotsichthys quadrimaculatus 0.00 0.00 7.47 1.31 0.00 7.19 0.00 0.00 15.97 7.11 Rastrelliger kanagurta 1.39 0.00 0.00 0.29 0.78 0.00 0.06 0.00 2.53 1.12 Sardines 0.00 0.00 0.00 0.75 0.22 0.00 0.00 5.15 6.13 2.73 Clupeidae 0.00 0.00 0.00 7.16 0.79 0.00 0.00 0.00 7.95 3.54 Engraulidae 0.00 0.00 0.00 0.02 0.00 0.01 0.00 0.00 0.03 0.01 Siganus fuscescens 0.43 0.00 0.00 1.24 0.00 0.00 0.00 0.00 1.67 0.74 Siganus guttatus 0.01 0.00 0.00 0.14 0.00 0.05 0.00 0.00 0.20 0.09 Siganus spinus 0.05 0.00 0.00 0.02 0.00 0.00 0.00 0.00 0.08 0.03 Sardinella lemuru 0.00 0.00 0.00 0.00 0.00 2.02 0.00 0.00 2.02 0.90 Lethrinidae 0.10 0.00 0.00 0.52 0.00 8.30 0.00 0.00 8.92 3.97 Loliginidae 0.00 0.00 0.00 0.27 1.14 0.00 0.00 0.00 1.41 0.63

Lutjanidae 0.10 0.00 0.00 0.00 0.00 0.17 0.02 0.00 0.29 0.13 Mugilidae 0.00 0.00 0.00 0.00 0.00 0.09 0.00 0.00 0.09 0.04 Others 0.18 0.00 0.00 12.87 7.09 1.75 0.55 1.23 23.66 10.54 Carangidae 0.00 0.00 0.00 0.00 0.00 0.01 0.00 0.00 0.01 0.01 Scaridae 0.29 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.29 0.13 Scombridae 0.00 0.00 0.00 0.00 0.00 0.11 0.00 0.00 0.11 0.05 Amblygaster sirm 0.00 0.00 0.00 0.38 0.00 0.00 0.00 0.00 0.38 0.17 Caesio caerulaurea 0.00 0.00 0.00 0.00 3.92 0.00 0.00 0.00 3.92 1.75 Caesio cuning 0.00 0.00 0.00 0.00 0.06 0.00 0.00 0.00 0.06 0.03 Acanthuridae 0.13 0.00 0.00 0.00 0.00 4.91 0.00 0.00 5.03 2.24 Sphyraenidae 0.02 0.00 0.00 0.09 0.00 0.25 0.07 0.00 0.43 0.19 5.45 21.69 22.18 25.19 19.30 24.86 25.55 80.33 224.54 100.00

C.11.4. Fishing Ground

Figure 55 shows where the monitored fishing gear types are usually operated. Information used in constructing this figure are from the recorded fishing ground of all fishing trips within the 2 month monitoring period. Note that frequently fished areas are denoted with large circle (24-40% and 15-25%), while small circles (0.2-4% and 0.04-6%) indicate least fished areas.

Most of the fishing activities are restricted inside the municipal waters. Although, fishers in each brgy are not restricted in fishing to other brgys. To some fishers, this is a problem (based on mini-FGDs conducted), because according to them, fishers from other brgys benefited instead of them. In Ayungon, the area within Brgy. Tampocon II and Anibong (Area A2) were the most fished. In Bindoy, the most fished areas are Brgy. Tinaogan (B2), adjacent deeper waters of Poblacion, Cabugan and Domolog (B9) and below (B9S).

Figure 55. Map showing where gears usually operates (a) Ayungon ( b) Bindoy from May- July 2016

D.1. Summary of Harvest Control Recommendations

In general, harvest control rules for the target species in Ayungon and Bindoy should include: D.1.1. Establishment of size limits in catches for the following species:

Selar crumenophthalmus 17.32cm SL Rastrelliger kanagurta 15.96cm SL Thysanoteuthis rhombus 55.80cm ML Caesio caerulaurea 22.09cm SL Siganus fuscescens 13.04cm SL Dussumieria elopsoides 10.90cm SL

D.1.2. Increase mesh size of drift gill nets and bottom set gill nets, to allow immature smaller fish to pass, and eventually grow, attain maturity and spawn. While the target for this measure are R. kanagurta, S. crumenophthalmus, S. fuscescens, C. caerulaurea and H. quadrimaculatus, it will also have a positive effect on other pelagic and softdemersal species caught by the gears, which make up 18-40% of the catch (others category). The measure, however, may reduce the catch of clupeids substantially because the targeted increase in mesh size will most likely allow clupeids, which are smaller in body depth and length, to swim through the meshes.

On the other hand, if a seasonal restriction to the use of drift gillnets and bottom set gill nets were to be enforced, it might be possible to retain the current mesh size, maintain catches of clupeids and reduce catches of juvenile R. kanagurta, S. crumenophthalmus, S. fuscescens and C. caerulaurea. Based on the literature, the spawning months for the target species are March to November (S. crumenophthalmus), May to September (R. kanagurta), March to May and August to October (S. fuscescens) March to August (H. quadrimaculatus), September to March E. punctifer) and July (E. heteroloba). A closed season for the use of drift gillnets and bottom set gill nets from March to November would protect spawners and juveniles of the target species, and perhaps of other pelagics and soft-demersal species as well.

Such measures will require extensive consultations since the closure will involve several months (i.e., 8 months). It would be best, however, if such measures were also backed by studies on local stocks since information from other fishing grounds may not necessarily hold for the southeast and the east coast of Negros Oriental. Other factors, like the value chain and employment, also need to be considered since these have a large contribution to the overall value of the resource.

D.1.3. Shift in gear use. Beach seines typically use fine (< 3cm stretch) mesh sizes so their catches are mostly made up of juvenile fish. Prohibiting the catching of juveniles will allow a larger portion of the stock to grow to maturity and contribute to the stock. Hence, establishment of closed season for beach seine operation is suggested specifically for Ayungon where this gear operates. This will benefit not only the target species, but all those species whose juveniles are routinely caught by the gear.

This however needs more detailed information before establishment (e.g. what month to close and how many months).

D.1.4. For giant squids, although the actual SPR are close (14%) and within (20%) the recommended value (20-30%), establishment of closed season is also suggested. This will sustain the fishery in the long run. As with the above, this needs more detailed information before establishment.

D.1.5. With these recommendations, spawning potential of the target stocks may be increased to the more acceptable range of 20-30%. Aside from the harvest control recommendations above, fisheries monitoring should be continued with the following improvements:

(i) A more detailed map of fishing zones should be used to allow reconstruction of spatial patterns of fishing and distribution of particular species (e.g., catch rates or where large and small individuals are found). Such information provide valuable insights to the different aspects of harvest control measures. (ii) Biological sampling (i.e., length measurements and maturity staging at least) should be done more frequently, and covering a longer time period (at least 12-16 months) to cover all size ranges caught in the fishery and all seasons.

(iii) The recording of catch and effort by enumerators and field assistants should be checked closely and regularly to make sure that proper and more complete information is recorded regularly. Frequent visits to the site in the initial months are critical for this.

(iv) It is important to note that field enumerators and field assistants can be easily trained to record catch and effort, but species identification, which is oftentimes overlooked or considered of little importance (vs common names) is critical and imperative. The use of scientific names is necessary since local names vary even between barangays, so that it is very common that a single common name may be used for 2 or more similar species, or that different common names are used for different life stages of the same species. Field guides and training on how to use them are important parts of the monitoring. In the same light, field-determined maturity stages should always be verified in the lab, unless sound expertise has been developed in the field.

(v) Efforts should be made to establish an LGU-implemented fisheries monitoring program to generate the data they need to be able to manage their resources properly for the long term.

(vi) Parallel laboratory-based studies, like ageing and fecundity studies, should be conducted for the target species to better understand more about critical processes (growth, recruitment) in their biology that are important in management of local stocks.

Data from the current monitoring program of RARE, under the Fish Forever Program, are not available for Negros Oriental. The program, however, has been implemented in other RARE sites for at least a few years now. Some of the improvements mentioned above may be taken up in the on-going monitoring effort, so that the resolution and representativeness of the data become more meaningful and useful for management. RARE has fellows in their various sites, and these may serve as catalysts for establishing fisheries monitoring programs in those sites where none have been initiated yet.

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Appendices

Appendix 1. One-on-one interview with fishermen in Ayungon and Bindoy, Negros Oriental (May 2016).

Appendix 2. Fisherman describing the squid jig gear (above) and group interview (below) in Ayungon and Bindoy, Negros Oriental (May 2016).

Appendix 3. Hands-on training of field assistants on processing fish samples in Ayungon and Bindoy, Negros Oriental (May 2016).

Appendix 4. Hands-on training of field enumerators in measuring mantle length of squids in Ayungon and Bindoy, Negros Oriental (May 2016).