Fishing is a significant source of food, and constitutes an important source of income in Turkey. Due to the large extent required to analyse the distribution of fish stocks, information derived from satellites play an important role in fisheries applications. Chlorophyll concentration and sea surface temperature (SST) are the most significant parameters which define the fish habitat. The accuracy of these parameters in the Black Sea taken from two different satellites, namely Sea-viewing Wide Field-of-views Sensor (SeaWIFS) and Moderate Resolution Imaging Spectroradiometer (MODIS) are evaluated. Results indicate that both satellites give good estimates of SST but the algorithms overestimate the chlorophyll concentration values. MODIS products are used in the subsequent analyses due to their high correlation with in-situ measurements relative to SeaWIFS products. The cause of the overestimation of chlorophyll concentration is further examined and a general description of environmental variability in Black Sea is done using MODIS products. Anchovy, the most important commercial fish in Turkey, has been selected as the target specie of the study. Level 3 weekly average MODIS chlorophyll and SST products are processed using remote sensing (RS) and geographic information systems (GIS) integration to estimate potential favorable zones for pelagic fish aggregations. Two different decision rules are employed to generate fish stock maps, simple additive weigthing (SAW) and fuzzy additive weigthing (FSAW). The resultant maps are used to visualize the general distribution of Anchovy in Turkish Seas from May 2000 to May 2001. The resultant thematic fish stock maps generated by FSAW analysis represents the uncertainity in the environment better than the ones generated by SAW analysis.

The uptake, distribution and depuration of a water soluble, mono-aromatic hydrocarbon contained in petroleum and refined products was studied in two species of marine fish, Nature northern anchovy (Engraulis mordax) and juvenile striped bass (Horone saxatilis) were exposed to sub-lethal concentrations of 14c benzene for 48 hours. Residues in tissues exhibiting a high lipid content (non-metabolic pathway) or representing apparent major metabolic sites were measured during the exposure and afterwards when the fish were transferred to clean seawater. Fish exhibited a rapid uptake over a wide range of benzene concentrations in the water column. Accumulation in anchovy was considerably greater than in striped bass. Results indicate that the pathway of hydrocarbons through the liver, gall bladder, intestines and colon is a major depuration route. Residues were depurated rapidly after cessation of exposure; in striped bass tissues. most residues were undetectable by seven days,

Florida's estuaries support a wide range of species yet little is known about tracemetal cycling among members of this important ecosystem. To examine the flow of trace metals through the Tampa Bay estuary, four fish species representing different trophic levels were analyzed for copper (Cu), zinc (Zn) and stable isotopes of carbon (C) and nitrogen (N). Species selected were the striped mullet (Mugil cephalus), tidewater mojarra (Eucinostomus harengulus), bay anchovy (Anchoa mitchilli), and sand seatrout (Cynoscion arenarius). Juvenile fish were collected from the Alafia, Hillsborough, Palm, and Little Manatee Rivers. Adults were collected from Tampa Bay. Combinations of trace metal and stable isotope analyses were used to evaluate geographic variability in trace metal concentrations among locations in Tampa Bay and to shed light on trophic pathways that lead to trace metal accumulation. In juvenile mullet, significant trends were found between Zn concentrations, stable isotope ratios, and standard length. Animals of the smallest size classes carry greater concentrations of zinc in their tissues and have distinct stable isotope ratios that reflect their recent life history as offshore planktivorous larvae. Interestingly, the ratio of Zn:Cu concentrations was highly conserved. While species-specific differences were observed, relatively small Zn:Cu variations suggest a possible bioregulatory mechanism that maintains an optimal Zn:Cu ratio even in the presence of elevated absolute metal concentrations. Stable isotope ratios proved to be an effective tracer of ontogenetic changes in fish diet and habitat. Carbon and nitrogen stable isotope analyses revealed that trophic relations between species are established very early in an organism's life history. The bay anchovy, a major prey item of the sand seatrout, has δ15N values very similar to this predator. Although trophic linkages between trace metals and stable isotopes proved difficult to interpret, the relation between zinc concentrations and δ¹³C values suggested that trace metal concentrations are highest in animals that utilize food webs based on terrestrial carbon.

La partie nord du Système du courant de Humboldt (NSCH) couvre moins de 0.1% de la surface océanique mondiale mais produit plus de poisons, en particulier d'anchois du Pérou (Engraulis ringens), par unité de surface que n'importe quelle autre région du monde. Bien que ce système produise suffisamment de macrozooplancton pour alimenter les populations de poisson fourrage, le manque d'informations sur ce compartiment limite nos capacités d'étude. L'objectif de cette thèse est d'étudier la dynamique de la distribution spatiotemporelle de la biomasse en macrozooplancton du NSCH en relation avec l'environnement physique et les poissons fourrage, à différentes échelles. Pour ce faire une méthode acoustique bi-fréquences a été développée et appliqué à des séries de données acoustiques historiques. Des informations à haute résolution ont ainsi pu être extraite sur la biomasse et les patrons de distribution du macrozooplancton, de la galathée pélagique 'munida', des poissons et des autres compartiments. Cette méthode nous a également permis d'estimer l'extension verticale de la communauté épipélagique (ZVEEC). Nous avons démontré que ZVEEC coïncide avec la limite supérieure de la zone de minimum d'oxygène (ZMO), ce qui permet de produire des donnés spatialisées à haute résolution de la limite supérieure de la ZMO et d'estimer le volume d'habitat de l'anchois. Notre estimation de biomasse en macrozooplancton, environ quatre fois supérieures aux estimations antérieures, est en accord avec les découvertes récentes sur l'écologie trophique des poissons fourrage du NSCH et fournit des éléments étayant les théories actuelles sur l'origine de la haute productivité en poissons du NSCH. L'étude des impacts des structures physiques de submeso- et mesoéchelle sur la distribution du macrozooplancton supporte l'hypothèse d'une structuration de type 'bottom-up'. Nous avons également mis en évidence l'impact de la structuration spatiale du macrozooplancton sur la distribution des poissons fourrage. Les données physiques et biologiques à haute résolution obtenues grâce à cette étude ouvrent de nouvelles perspectives pour réaliser des études écologiques intégrées à échelles multiples et pour calibrer les modèles biogéochimiques, trophiques ou End-to-End. / The Northern Humboldt Current system (NHCS) represents less than 0.1% of the world ocean surface but produces more fish, mainly Peruvian anchovy (Engraulis ringens), per unit area than any other region in the world. Although this system produces enough macrozooplankton to feed its high production of forage fish, the paucity of information on zooplankton hampers research in the system. The objective of this study was to investigate the multiscale dynamics of the spatiotemporal distribution of the macrozooplankton biomass off Peru in relation to the physical environment and their fish predators. For that a bi-frequency acoustic method was developed and applied to extract, from historical acoustic data, high-resolution information on the biomass and the patterns of distribution of macrozooplankton, the pelagic red squad 'munida', fish and other marine compartments. This method also allows estimating the vertical extension of this epipelagic community (ZVEEC). We demonstrated that ZVEEC coincide with the upper limit of the oxygen minimum zone (OMZ), which allowed both producing high-resolution spatial data of the upper limit of the OMZ and estimating the volume habitat of anchovy. The estimated macrozooplankton biomass was about four times higher than previously reported. This estimate is in agreement with the recent findings on forage fish trophic ecology and supports the current hypotheses explaining the NHCS high fish production. The study of the impacts of the submeso- and mesoscale physical structures on macrozooplankton provided evidence of the bottom-up physical effect on the distribution of macrozooplankton biomass. We also found further evidence of the structuring bottom-up effect that macrozooplankton exert on forage fish. The high-resolution biological and physical data obtained in this study opens new perspective to perform integrated multiscale ecological studies and to calibrate biogeochemical, trophic and End-to-End models.

Στην παρούσα εργασία πραγματοποιήθηκε εκτίμηση της αναπαραγόμενης βιομάζας του ευρωπαϊκού γαύρου, Engraulis encrasicolus, στην περιοχή του Βορειοανατολικού Αιγαίου (Θρακικό Πέλαγος, Κόλπος Καβάλας, Στρυμωνικός Κόλπος, Λήμνος) τα έτη 2003 και 2004 με τη Μέθοδο Ημερήσιας Παραγωγής Αβγών (DEPM). Για την εφαρμογή της μεθόδου πραγματοποιήθηκαν δύο ωκεανογραφικά ταξίδια με το Ε/Σ «ΦΙΛΙΑ» κατά το μέγιστο της ωοτοκίας του γαύρου τον Ιούνιο του 2003 και του 2004. Στη διάρκεια τους συλλέχθηκαν δείγματα ιχθυοπλαγκτού για την εκτίμηση της ημερήσιας παραγωγής αβγών, ενώ πραγματοποιήθηκαν και λήψεις κατακόρυφων διατομών θερμοκρασίας και αλατότητας σε εκτεταμένο δίκτυο σταθμών. Παράλληλα, πραγματοποιήθηκαν δειγματοληψίες ενήλικων ατόμων γαύρου είτε επί του επαγγελματικού στόλου των γρι-γρι της περιοχής, είτε με την πελαγική τράτα του «ΦΙΛΙΑ», τα οποία χρησιμοποιήθηκαν για την εκτίμηση της αναλογίας φύλου, της γονιμότητας ομάδας, της συχνότητας ωοτοκίας και του μέσου βάρους των θηλυκών. Όσον αφορά στις περιβαλλοντικές συνθήκες, το 2003 παρατηρήθηκε αυξημένη στρωματοποίηση των υδάτων, χαμηλότερη επιφανειακή αλατότητα και υψηλότερες τιμές χλωροφύλλης-α, διαφορές που πιθανώς οφείλονται σε αυξημένη εκροή νερού της Μαύρης Θάλασσας. Και τα δύο έτη η βιομάζα του ζωοπλαγκτού ήταν περίπου ίδια. Μέσω απλής ανάλυσης πηλίκου για το χαρακτηρισμό του αναπαραγωγικού ενδιαιτήματος του γαύρου, βρέθηκε ότι και τις δύο χρονιές η ωοτοκία πραγματοποιήθηκε σε νερά με χαμηλή αλατότητα (<34.5), πλούσια σε χλωροφύλλη-α και ζωοπλαγκτό. Αντίθετα, τα θερμοκρασιακά εύρη κατά τις δύο χρονιές διέφεραν, γεγονός που φαίνεται να αντανακλά περισσότερο τις διαφορές θερμοκρασίας ανάμεσα στα δύο έτη παρά διαφορετική προτίμηση για ωοτοκία. Επιπλέον, το 2004 η παραγωγή αβγών ήταν μειωμένη, το πεδίο αναπαραγωγής είχε συρρικνωθεί και η ωοτοκία ήταν επικεντρωμένη στην περιοχή του Θρακικού. Για την εκτίμηση της συχνότητας ωοτοκίας πραγματοποιήθηκε ιστολογική ανάλυση των θηλυκών γονάδων του γαύρου, από την οποία προέκυψε ότι ενώ τα στάδια ανάπτυξης των υγιών ωοκυττάρων ήταν παρόμοια με περιγραφές για το είδος Engraulis mordax, τα στάδια της ατρησίας παρουσίασαν ορισμένες διαφορές. Αυτές αφορούσαν στην εμφάνιση καφε-κίτρινων χρωστικών (χαρακτηριστικό γνώρισμα της δ-ατρησίας) στο τέλος της β-ατρησίας. Επιπλέον, η απορρόφηση των κενών ωοθυλακίων διαρκούσε δύο ημέρες σε αντίθεση με παρατηρήσεις για το Engraulis mordax, όπου παρατηρούνταν και κενά ωοθυλάκια τριών ημερών, διαφορά που οφείλεται στις υψηλότερες θερμοκρασίες του ΒΑ. Αιγαίου σε σχέση με περιοχές αναβλύσεων. Οι παράμετροι των ενηλίκων που προέρχονταν από δείγματα της επαγγελματικής και πειραματικής αλιείας δεν εμφάνισαν σημαντικές διαφορές μεταξύ τους. Αντίθετα, διαφορές παρατηρήθηκαν ανάμεσα στα δύο έτη όσον αφορά στις παραμέτρους του μέσου βάρους, της συχνότητας ωοτοκίας και της γονιμότητας. Συγκεκριμένα, το 2004 τα ψάρια ήταν βαρύτερα, πιο εύρωστα και απελευθέρωναν μεγαλύτερο αριθμό αβγών ανά μικρότερα χρονικά διαστήματα. Αν λάβει κανείς υπ’όψιν ότι το 2004 η αναπαραγόμενη βιομάζα ήταν σημαντικά μικρότερη ενώ η βιομάζα του ζωοπλαγκτού παρέμεινε η ίδια, οι παραπάνω διαφορές μπορούν να εξηγηθούν από φαινόμενα εξάρτησης των παραμέτρων αυτών από την πυκνότητα του πληθυσμού (density dependence). Η αναπαραγόμενη βιομάζα το 2004 (6251t) ήταν σημαντικά μειωμένη και αντιστοιχούσε σχεδόν στο 1/3 της βιομάζας του 2003 (17600t). Η μείωση αυτή πιθανώς να οφείλεται σε συνδυασμό έντονης αλιευτικής πίεσης και χαμηλών επιπέδων στρατολόγησης της ηλικιακής κλάσης του 2003. / The spawning biomass of the European anchovy, Engraulis encrasicolus, stock in the N.E. Aegean Sea was estimated by means of the Daily Egg Production Method (DEPM) for the years 2003 and 2004. Two oceanographic surveys were conducted with the R/V “PHILIA” during the maximum reproductive activity of the anchovy population in June 2003 and 2004. Ichthyoplankton sampling and vertical profiles of temperature and salinity were performed over an extensive grid of stations. At the same time adult anchovy samples were collected either on board the commercial purse-seine fleet or by means of an experimental pelagic trawl operated by “PHILIA”. The adult samples were used to estimate parameters of the DEPM: sex ratio, mean female weight, batch fecundity and spawning frequency. Significant interannual differences were found in the environmental conditions. In June 2003 the water column was more stratified, less saline (5m) and richer in chlorophyll-α, which probably were due to larger outflow of Black Sea Water (BSW). The zooplankton biomass remained the same during 2003 and 2004. A simple quotient rule analysis was applied to characterize the spawning habitat of anchovy. In both years anchovy spawning appeared to take place in less saline waters (34.5), rich in chlorophyll-α and zooplankton. On the contrary, anchovy spawning appeared to take place over different temperature range in the two years. This rather reflects different temperature values in 2003 and 2004 than different selection for spawning. In 2004 the daily egg production was reduced, the spawning area was limited and the spawning activity took place mainly in the Thracian Sea. Histological analysis of the female anchovy gonads was carried out in order to estimate the spawning frequency. The developmental stages of healthy oocytes were similar to those of the species Engraulis mordax. However, the atresia stages were different with regard to the appearance of brown-yellow pigments at the end of beta stage atresia instead of the end of delta stage atresia. Moreover, the absorption of the postovulatory follicle lasted two days instead of three days. The higher temperatures in the N.E. Aegean Sea were responsible for the shorter duration of the postovulatory follicle absorption. There were no statistically significant differences between DEPM adult parameters calculated from purse-seine samples compared to pelagic trawl samples. On the contrary, mean female weight, fecundity and spawning frequency showed statistically significant differences between the two years. In 2004 the anchovies were in better condition and produced numerous eggs in short interspawning intervals. Since the estimated biomass was lower in 2004 while the zooplankton biomass remained stable, it seems that density-dependence phenomena could justify the interannual differences. The estimated spawning biomass in 2004 (6251t) was significantly lower compared to that of 2003 (17600t). Intense fishing effort and low levels of recruitment of the 2003 cohort are probably responsible for this decrease.

Le Système Nord du Courant de Humboldt (SNCH) est le lieu d’une forte activité biologique due à un upwelling côtier intense. Il abrite l’une des plus grandes populations de l’anchois du Pérou soumis à la plus grande pêcherie monospécifique au monde. Le SNCH héberge aussi de grandes et variables, populations d’oiseaux, composées de trois espèces sympatriques productrices de guano : le cormoran guanay (Phalacrocorax bougainvillii), le fou péruvien (Sula variegata) et le pélican péruvien (Pelecanis thagus), qui se nourrissent principalement d’anchois. Dans ce travail, nous examinons les fluctuations de ces trois populations d’oiseaux marins, en nous concentrant sur le cycle saisonnier de leur reproduction, pour aborder les questions suivantes : Dans quelle mesure les saisonnalités de reproduction diffèrent elles entre espèces ? Dans quelle mesure sont-elles plastiques dans le temps et dans l’espace ? Qu’est ce qui, des conditions environnementales et des activités anthropogéniques affecte le plus la reproduction des oiseaux marins ? Nous abordons ces questions en utilisant des données de présence de reproducteurs (1) dans 30 sites péruviens répartis entre 06°S-18°S (2003-2014) ; et (2) dans un site, pendant trois périodes (1952-1968, 1972-1989, 2003-2014). Nous utilisons des covariables environnementales décrivant les conditions océanographiques, l’abondance, l’accessibilité et la condition des proies, ainsi que des covariables décrivant la pression de pêche. Nous utilisons des modèles d’occupation multi-saisonniers pour caractériser la saisonnalité de la reproduction et la relier aux covariables environnementales. Nous utilisons aussi des analyses en composantes principales fonctionnelles pour classifier les différences de saisonnalité entre sites, et des forêts aléatoires de régression pour analyser la contribution relative des covariables à la variabilité de la saisonnalité de reproduction.Nous mettons en évidence qu’en moyenne, la reproduction démarre au cours de l’hiver austral / début de printemps et prend fin en été / début d’automne, ce patron étant plus marqué chez les fous et pélicans que chez les cormorans. La reproduction est calée dans le temps de telle sorte à ce que les jeunes prennent leur indépendance lorsque les conditions de production primaire, d’abondance et d’accessibilité des proies sont maximales. Ce patron est unique en comparaison avec les autres écosystèmes d’upwelling et peut être expliqué par les fortes abondances absolues de proies disponibles tout au long de l’année dans le SNCH.La saisonnalité de reproduction diffère entre les sites de nidification. Les oiseaux se reproduisent plus tôt et avec de plus fortes probabilités lorsque les colonies sont plus grandes, situées sur des îles à moins de 20 km des côtes, aux plus basses latitudes, et présentant une production primaire plus élevée. Alors, la saisonnalité de la reproduction est davantage influencée par les conditions environnementales locales que par les gradients environnementaux de grande échelle.Les oiseaux marins adaptent aussi la saisonnalité de leur reproduction aux changements drastiques causés dans l’écosystème par les changements de régime. Les cormorans font preuve de la plus grande plasticité, en modulant la date te l’amplitude de la saisonnalité de leur reproduction, cela est probablement permis par leur plus grande flexibilité de fourragement. Les dates et amplitudes fixes observées chez les fous peuvent être liées aux spécificités de leur stratégie de fourragement et à des changements de proies lorsque le stock d’anchois est bas. Les différences spécifiques dans les adaptations de la saisonnalité de reproduction permettent aux oiseaux de profiter différemment des conditions locales de proies, et de faire face aux changements de régime avec des stratégies différentes. Une méthodologie de capture-recapture en parallèle des comptages mensuels est proposée pour élargir les horizons de l’évaluation des dynamiques d’une population. / The Northern Humboldt Current System (NHCS) is a place of a high biological activity due to an intense coastal upwelling. It supports one of the biggest forage fish populations, the Peruvian anchovy, and the world-leading monospecific fishery in terms of landings. The NHCS also hosts large, although variable, seabird populations, composed among others by three guano-producing sympatric species: the Guanay cormorant (Phalacrocorax bougainvillii), the Peruvian booby (Sula variegata) and the Peruvian pelican (Pelecanus thagus), which all feed primarily on anchovy.In this work we reviewed the fluctuations of these three seabird populations, focusing on the seasonal cycle of their breeding, to address the following questions: How different are the seasonality of reproduction among species? To what extent may they be plastic in space and time? What from the natural environment and the anthropogenic activities impact more the breeding of seabirds?We addressed these questions using the monthly occupancy of breeders (1) in >30 Peruvian sites between 06°S and 18°S and from 2003 to 2014; and (2) in one site during three decadal periods (1952-1968, 1972-1989, 2003-2014). We also used environmental covariates from satellite and at-sea monitoring such as oceanographic conditions, prey abundance, availability and body conditions, and fisheries pressure covariates. We used multiseason occupancy models to characterize the seasonality of breeding and relate it with environmental covariates. We also used functional principal component analysis for classifying the differences in seasonality among sites, and random forest regression for analyzing the relative contribution of covariates in the variability of the seasonal breeding.We found that in average seasonal breeding mainly started during the austral winter/ early spring and ended in summer/ early fall, this pattern being stronger in boobies and pelicans than in cormorants. The breeding onset of seabirds is timed so that fledging independence occurs when primary production, prey conditions and availability are maximized. This pattern is unique compared with other upwelling ecosystems and could be explained by the year-round high abundances of anchovy in the NHCS.The average seasonal breeding may differ among nesting sites. Seabirds breed earlier and are more persistent when colonies are larger, located on islands, within the first 20km of the coast, at lower latitudes and with greater primary production conditions. These results suggest that in the NHCS, the seasonality of breeding is more influenced by local environmental conditions than by large-scale environmental gradients. These results provides critical information to a better coordination of guano extraction and conservancy policies.Seabirds may also adapt the seasonality of their breeding to drastic ecosystem changes caused by regime shifts. We found that the three study species exhibited a gradient of plasticity regarding the seasonality of their breeding. Cormorants showed a greater plasticity, modulating the timing and magnitude on their breeding seasonality. This is probably authorized by the greater foraging flexibility offered its great diving capacities. Fixed onset and magnitudes of breeding in boobies may be related to their specific foraging strategy and/or to changes of prey items when anchovy stock was low. We also suggested that boobies may adapt other fecundity traits as growth rate of chicks to lower abundance of anchovy.The specific differences in the adaptation of seasonal breeding allow seabirds to take profit differently from local prey conditions or to face differently regime shifts. Further researches, implementing a large-scale capture-recapture methodology in parallel with monthly census, are proposed in order to fulfill gaps in the basic knowledge on vital traits (adult survival, first age at reproduction, and juvenile recruitment) which are critical parameters to evaluate the dynamic of a population.

Nos estudos de populações pesqueiras é comum o uso de modelos hidrodinâmicos acoplados a modelos biológicos e, um tipo de modelo merece destaque: o baseado no indivíduo (IBM). A Plataforma Continental do Atlântico Sudoeste comporta uma importante atividade pesqueira e, a influência da circulação na distribuição de ovos/larvas nessa região é pouco entendida. Estudos anteriores sugerem que o transporte de Ekman em direção à costa e o deságue de água fluvial impedem a perda de ovos e larvas da área costeira. Este trabalho apresenta resultados de um estudo englobando os padrões de circulação e de transporte de larvas nessa área, realizado através do desenvolvimento de um IBM para os estágios iniciais da Engraulis anchoita e o acoplamento deste a dois campos de velocidade superficial: a de Ekman, e a saída de um modelo hidrodinâmico 3D. Os resultados mostram que somente a deriva de Ekman não é suficiente para explicar o padrão de retenção larval observado na região. Os valores de retenção encontrados com a utilização da saída do modelo estão próximos aos observados. Maiores concentrações larvais foram obtidas no outono/inverno e menores na primavera/verão. Estes resultados estão diretamente relacionados à combinação dos efeitos dos padrões de vento da área com a influência das Correntes do Brasil e das Malvinas e do deságue continental na circulação sobre a plataforma. / Recruitment of pelagic fishes is the net result a series of continuous events in their life cycle. Most of the variability in natural mortality is thought to occur during the early stages of development and is related to environmental factors. The use of coupled physical-biological modeling in the study of fisheries populations is very common and a particular type of model deserves special mention: the Individual Based Model (IBM). The Atlantic Southwestern Continental Shelf is one of the most productive fishing sites in the Western South Atlantic, but the processes involving the circulation in this area and its influence on eggs/larvae transport and retention are still poorly understood. Recent studies describe the spawning activity of anchovy and its relationship to oceanographic processes and suggest that predominant onshore Ekman transport, during the austral winter/spring, keeps the eggs and larvae in coastal areas. According to these studies, the river runoff contributes to the formation of a retention zone for planktonic organisms over the area. This work presents results of a study that considers both the circulation pattern and larval transport, throught the development of an IBM for the early stages of anchovy Engraulis anchoita. The model is coupled to two surface velocity fields: the Ekman drift, and the output of a 3D hydrographic model. The results show that just Ekman surface velocities are not able to explain the larval dispersion observed in this region. Retention values obtained with the model output are much closer to observed values. Autumn and winter seasons present the highest values of retention. These results are due to the combined effect of the wind patterns registered in the area with the influence of the river runoff and the Brazil-Malvinas shelf circulation.

Atualmente, a pesca de pequena escala enfrenta diversas dificuldades, dentre as quais se destacam as deficiências estruturais de armazenamento, conservação e processamento do pescado, mas também dos processos de distribuição e comercialização. Uma das principais necessidades de conhecimento consiste no mapeamento e compreensão dos processos e elos das cadeias produtivas das pescarias artesanais. O objetivo desse estudo foi tecer uma investigação comparativa focada na estrutura, função, e desempenho das cadeias produtivas de três sistemas pesqueiros do Estado de São Paulo com significância socioeconômica: o da corvina (Micropogonias furnieri) capturada por redes de emalhe em Ubatuba; o do camarão sete-barbas (Xiphopeneaus kroyeri) capturado por redes de arrasto, no Rio do Meio, Guarujá; e o da manjuba (Anchoviella lepidentostole) capturada por redes de emalhe na Barragem do Valo Grande, em Iguape. Os dados de campo foram coletados durante o período de março/2013 a janeiro/2015 por meio de questionários aplicados em entrevistas com os atores envolvidos nos processos de captura, processamento, distribuição e comercialização do pescado. A cadeia produtiva da manjuba se mostrou como a mais complexa do grupo, com maior número de atores e fluxos de distribuição, alta abrangência de distribuição e diferentes tipos de processamento. Quanto à distribuição dos benefícios, a maior margem de comercialização foi verificada na planta de processamento da cadeia do camarão, enquanto que a menor foi a dos atravessadores das cadeias da corvina e da manjuba. O produto final com maior valor de comercialização no varejo foi a da manjuba eviscerada (7,6 vezes maior que o valor de primeira comercialização). Em relação ao desempenho das cadeias estudadas, os indicadores de equidade, eficiência, e empoderamento apresentaram baixa adesão, sugerindo uma necessidade de melhorias em todos os segmentos. A partir dos métodos e resultados deste estudo, tópicos importantes sobre as cadeias produtivas e de valores da pesca de pequena escala, poderão servir de base para a definição de políticas de gestão mais eficientes visando a sustentabilidade do setor, ou ainda, para a melhoria da qualidade do pescado e dos segmentos envolvidos nessas atividades. / Currently, small-scale fisheries face several difficulties, such as structural deficiencies for fish storage and preservation, but also in the process of distribution and marketing. One of the main knowledge gap is the mapping and understanding of the processes and links of the small-scale fisheries value chains. In this study, a comparative investigation focused on the structure, function and performance of supply chains from three fishery systems with significative socioeconomic relevance in São Paulo State was performed. The systems comprise the whitemouth croaker (Micropogonias furnieri) fishery by gillnetters in Ubatuba, the seabob-shrimp (Xiphopeneaus kroyeri) fishery by Rio do Meio\'s trawlers in Guarujá, and the broadband anchovy (Anchoviella lepidentostole) fishery by canoes with gillnets in the Valo Grande Dam, in Iguape. The data were collected at field from March/2013 to January/2015 through questionnaires and inperson surveys with the actors involved in the processes of catch, processing, distribution and sale. The supply chain of broadband anchovy proved to be the most complex, with highest number of actors and distribution flows, high range of distribution and different processing forms. On the distribution of benefits, the highest marketing margin was verified in the processing plant of the seabob-shrimp\'s chain, while the lowest, was identified in the middlemen of croaker and anchovy chains. The final product with largest retail sale value was the eviscerated broadband anchovy (about 7.6 times higher than the first sale value). In regard to equity, efficiency and empowerment criteria on value chains performance, the three fishery systems showed low compliance in all considered indicators, suggesting a need for improvements in all segments. This study obtained relevant details on the supply and value chain of the three small-scale fisheries of São Paulo. These data and the methods proposed may support the definition of management policies more efficient for the sector\'s sustainability, in addition, to improve the quality of fish and human segments involved in these activities.

Nos estudos de populações pesqueiras é comum o uso de modelos hidrodinâmicos acoplados a modelos biológicos e, um tipo de modelo merece destaque: o baseado no indivíduo (IBM). A Plataforma Continental do Atlântico Sudoeste comporta uma importante atividade pesqueira e, a influência da circulação na distribuição de ovos/larvas nessa região é pouco entendida. Estudos anteriores sugerem que o transporte de Ekman em direção à costa e o deságue de água fluvial impedem a perda de ovos e larvas da área costeira. Este trabalho apresenta resultados de um estudo englobando os padrões de circulação e de transporte de larvas nessa área, realizado através do desenvolvimento de um IBM para os estágios iniciais da Engraulis anchoita e o acoplamento deste a dois campos de velocidade superficial: a de Ekman, e a saída de um modelo hidrodinâmico 3D. Os resultados mostram que somente a deriva de Ekman não é suficiente para explicar o padrão de retenção larval observado na região. Os valores de retenção encontrados com a utilização da saída do modelo estão próximos aos observados. Maiores concentrações larvais foram obtidas no outono/inverno e menores na primavera/verão. Estes resultados estão diretamente relacionados à combinação dos efeitos dos padrões de vento da área com a influência das Correntes do Brasil e das Malvinas e do deságue continental na circulação sobre a plataforma. / Recruitment of pelagic fishes is the net result a series of continuous events in their life cycle. Most of the variability in natural mortality is thought to occur during the early stages of development and is related to environmental factors. The use of coupled physical-biological modeling in the study of fisheries populations is very common and a particular type of model deserves special mention: the Individual Based Model (IBM). The Atlantic Southwestern Continental Shelf is one of the most productive fishing sites in the Western South Atlantic, but the processes involving the circulation in this area and its influence on eggs/larvae transport and retention are still poorly understood. Recent studies describe the spawning activity of anchovy and its relationship to oceanographic processes and suggest that predominant onshore Ekman transport, during the austral winter/spring, keeps the eggs and larvae in coastal areas. According to these studies, the river runoff contributes to the formation of a retention zone for planktonic organisms over the area. This work presents results of a study that considers both the circulation pattern and larval transport, throught the development of an IBM for the early stages of anchovy Engraulis anchoita. The model is coupled to two surface velocity fields: the Ekman drift, and the output of a 3D hydrographic model. The results show that just Ekman surface velocities are not able to explain the larval dispersion observed in this region. Retention values obtained with the model output are much closer to observed values. Autumn and winter seasons present the highest values of retention. These results are due to the combined effect of the wind patterns registered in the area with the influence of the river runoff and the Brazil-Malvinas shelf circulation.

Atualmente, a pesca de pequena escala enfrenta diversas dificuldades, dentre as quais se destacam as deficiências estruturais de armazenamento, conservação e processamento do pescado, mas também dos processos de distribuição e comercialização. Uma das principais necessidades de conhecimento consiste no mapeamento e compreensão dos processos e elos das cadeias produtivas das pescarias artesanais. O objetivo desse estudo foi tecer uma investigação comparativa focada na estrutura, função, e desempenho das cadeias produtivas de três sistemas pesqueiros do Estado de São Paulo com significância socioeconômica: o da corvina (Micropogonias furnieri) capturada por redes de emalhe em Ubatuba; o do camarão sete-barbas (Xiphopeneaus kroyeri) capturado por redes de arrasto, no Rio do Meio, Guarujá; e o da manjuba (Anchoviella lepidentostole) capturada por redes de emalhe na Barragem do Valo Grande, em Iguape. Os dados de campo foram coletados durante o período de março/2013 a janeiro/2015 por meio de questionários aplicados em entrevistas com os atores envolvidos nos processos de captura, processamento, distribuição e comercialização do pescado. A cadeia produtiva da manjuba se mostrou como a mais complexa do grupo, com maior número de atores e fluxos de distribuição, alta abrangência de distribuição e diferentes tipos de processamento. Quanto à distribuição dos benefícios, a maior margem de comercialização foi verificada na planta de processamento da cadeia do camarão, enquanto que a menor foi a dos atravessadores das cadeias da corvina e da manjuba. O produto final com maior valor de comercialização no varejo foi a da manjuba eviscerada (7,6 vezes maior que o valor de primeira comercialização). Em relação ao desempenho das cadeias estudadas, os indicadores de equidade, eficiência, e empoderamento apresentaram baixa adesão, sugerindo uma necessidade de melhorias em todos os segmentos. A partir dos métodos e resultados deste estudo, tópicos importantes sobre as cadeias produtivas e de valores da pesca de pequena escala, poderão servir de base para a definição de políticas de gestão mais eficientes visando a sustentabilidade do setor, ou ainda, para a melhoria da qualidade do pescado e dos segmentos envolvidos nessas atividades. / Currently, small-scale fisheries face several difficulties, such as structural deficiencies for fish storage and preservation, but also in the process of distribution and marketing. One of the main knowledge gap is the mapping and understanding of the processes and links of the small-scale fisheries value chains. In this study, a comparative investigation focused on the structure, function and performance of supply chains from three fishery systems with significative socioeconomic relevance in São Paulo State was performed. The systems comprise the whitemouth croaker (Micropogonias furnieri) fishery by gillnetters in Ubatuba, the seabob-shrimp (Xiphopeneaus kroyeri) fishery by Rio do Meio\'s trawlers in Guarujá, and the broadband anchovy (Anchoviella lepidentostole) fishery by canoes with gillnets in the Valo Grande Dam, in Iguape. The data were collected at field from March/2013 to January/2015 through questionnaires and inperson surveys with the actors involved in the processes of catch, processing, distribution and sale. The supply chain of broadband anchovy proved to be the most complex, with highest number of actors and distribution flows, high range of distribution and different processing forms. On the distribution of benefits, the highest marketing margin was verified in the processing plant of the seabob-shrimp\'s chain, while the lowest, was identified in the middlemen of croaker and anchovy chains. The final product with largest retail sale value was the eviscerated broadband anchovy (about 7.6 times higher than the first sale value). In regard to equity, efficiency and empowerment criteria on value chains performance, the three fishery systems showed low compliance in all considered indicators, suggesting a need for improvements in all segments. This study obtained relevant details on the supply and value chain of the three small-scale fisheries of São Paulo. These data and the methods proposed may support the definition of management policies more efficient for the sector\'s sustainability, in addition, to improve the quality of fish and human segments involved in these activities.