Sensory Quality and Shelf Life of MAP Redfish (Sebastes marinus) Fillets as Affected by Previous MA Bulk Storage of Whole Fish

Abstract

The shelf life of iced redfish is known to be 16–19 days. This study evaluated the effects of modified atmosphere (CO₂/N₂: 60/40) in bulk storage of redfish and subsequent modified atmosphere packaging (MAP) of fillets. Fish were evaluated by sensory, microbiological and chemical methods. Modified atmosphere (MA) bulk storage of whole fish for more than 5 to 10 days did not improve their sensory quality or significantly increase shelf life. In fact, the study showed negative effects in texture and overall appearance. MAP of fillets processed from 10-day MA bulk stored fish showed a modest increase in shelf life, but negatively affected their texture. Sensory qualities, i.e., tenderness, that decreased under MA bulk storage were improved upon aerobic storage for fish stored under MA for 5 to 10 days, but not 14 days. Lower microbial levels were found in MA bulk stored fish and MAP fillets compared to traditionally iced fish, while higher TMA levels were found in MAP fillets.     

A Comparative Study on the Quality Changes of Croaker (Johnius dussumieri) Fish Stored in Slurry Ice and Flake Ice

In the present study, the effect of storage in slurry ice compared to conventional flake ice (control) on the quality of croaker (Johnius dussumieri) fish was evaluated. Biochemical, microbiological, and sensory analyses were performed. Total volatile base nitrogen, trimethylamine nitrogen, and pH values were lower for fish stored in slurry ice than in control. Similarly, aerobic plate count and Pseudomonas sp. count were also found at lower population levels in fish stored in slurry ice. Texture profile analysis revealed that fish stored in slurry ice showed improved texture. Based on the microbiological and sensory analysis, the shelf life of croaker fish stored in slurry ice was 15 days.     

Microbial Growth Models in Gilthead Sea Bream (Sparus aurata) Stored in Ice

ABSTRACT

This study analyzes microbiological changes in whole, ungutted farmed gilthead sea bream (Sparus aurata) stored for an 18-day period in ice using traditional methods for mesophilic aerobic bacteria, psychrotrophic, Pseudomonas spp., Aeromonas spp., Shewanella putrefaciens, Enterobacteriaceae, sulphide-reducing Clostridium (Clostridia), and Photobacterium phosphoreum in muscle, skin, and gills, evaluating their seasonal differentiation. Two different statistical models were used to analyze microbiological growth. Simultaneously, physicochemical parameters such as the temperature, pH, biological oxygen demand (BOD), total dissolved solids, salinity, ammonia nitrogen, and total phosphorus content of growing waters were analyzed. The results showed that by the end of the storage time, specific spoilage bacteria (SSB) such as Pseudomonas spp., Aeromonas spp., and S. putrefaciens as H₂S-producing bacteria were dominant in sea bream harvested in temperate water in the Canary Islands. Muscle tissue had the least contamination, followed by skin and gills. The values of the analyzed seawater parameters were constant during the four seasons, except that the temperature showed a small difference between winter and summer. Seasonal effects were observed among the fish analyzed, suggesting that the lower levels of contamination detected in winter may have been due to the slight difference observed in water temperature in that season.     

The Combined Efficacy of Superchilling and High CO2 Modified Atmosphere Packaging on Shelf Life and Quality of Swimming Crab (Portunus trituberculatus)

The combined effect of superchilling and modi?ed atmosphere packaging (MAP) treatment on the quality of swimming crab during storage was investigated. As a result, signi?cantly (p < 0.05) higher inhibitor effects on total aerobic plate counts (TPCs) were observed in MAP treatments than in control (air package). Additionally, chemical analysis results showed that MAP treatments with 40–80% carbon dioxide (CO₂) were highly effective in maintaining lower total volatile basic-nitrogen (TVB-N), trimethylamine-nitrogen (TMA-N), pH, and thiobarbituric acid reactive substances (TBARS) values in swimming crab (p < 0.05). On the other hand, the brightness (L*) results also con?rmed that this combined treatment showed a positive effect on the stability of color during storage. Results also indicated that the combination of superchilling and 60% CO₂ MAP treatment prolonged the shelf life of swimming crab to 15–20 days. However, 100% CO₂ MAP treatment showed a negative effect on the drip loss and overall acceptability, indicating CO₂ content should be considered as a critical factor in this promising technology.     

Quality Index Method (QIM) Scheme Developed for Whole Nile Tilapias (Oreochromis niloticus) Ice Stored under Refrigeration and Correlation with Physicochemical and Microbiological Quality Parameters

ABSTRACT

A quality index method (QIM) scheme was optimized to evaluate the freshness of whole tilapias (Oreochromis niloticus) ice stored under refrigerated conditions, which is the most common format of commercialization between primary producers and retailers. QI showed a high prediction accuracy, estimating a rejection point of 10.8 days. Principal component analysis showed the influence of the storage time on sensory, physicochemical (instrumental color and texture profile, total volatile base nitrogen, thiobarbituric acid-reactive substances, pH), and microbiological (total aerobic mesophilic count and total aerobic psychrotrophic count) quality parameters and the correlations between them. The suitability of the QIM scheme for assessing the freshness of whole tilapia was demonstrated to be a fast and accurate tool to maintain proper quality control along the production chain.     

Effects of dietary fatty acid composition on metabolic rate and responses to hypoxia in the European eel (Anguilla anguilla)

European eels (Anguilla anguilla, L.) were fed on a commercial diet supplemented either with 15% by dry feed weight of menhaden oil (MO), an oil rich in highly unsaturated fatty acids of the n-3 series (n-3 HUFA), or with 15% by dry feed weight of coconut oil (CO), an oil composed primarily of saturated fatty acids (SFA). Following 90 days of feeding, the mean final masses of eels fed the two different oil supplements were similar, and higher than the mean final mass of a group fed the commercial diet alone. The diets created two distinct phenotypes of eels, distinguished by the fatty acid (FA) composition of their tissue lipids. Eels fed MO had significantly more total n-3 FA and n-3 HUFA in muscle and liver lipids than did eels fed CO, leading to higher n-3/n-6 and eicosapentaenoic acid/arachidonic acid ratios in the MO group. Measurements of O₂ uptake (M_O2) revealed that the MO group had a significantly lower routine metabolic rate (RMR) than the CO group. When exposed to progressive hypoxia, both groups regulated M_O2 at routine normoxic levels until critical water O₂ partial pressures that were statistically similar (9.62±1.08 kPa in MO versus 7.57±1.07 kPa in CO), beyond which they showed a reduction in M_O2 below RMR. The MO group exhibited a significantly lower M_O2 than the CO group throughout hypoxic exposure, but the percentage reductions in M_O2 below their relative RMR were equal in both groups. During recovery to normoxia, both groups exhibited an increase in M_O2 to rates significantly higher than their RMR. Throughout recovery, M_O2 was significantly lower in the MO group compared with the CO group, but the percentage increases in M_O2 relative to RMR were equal in both. During progressive hypoxia, neither group exhibited a marked ventilatory reflex response, both showed similar reductions in blood O₂ partial pressure and content, and similar increases in plasma lactate. The results indicate that, although the n-3 HUFA-enriched MO group had a significantly lower routine metabolic rate than the CO group, the difference in aerobic metabolism did not influence the European eel's homeostatic regulation of M_O2 in hypoxia.     

Evaluation of Quality Parameters in the Meat of Pintado Amazônico,Female Pseudoplatystoma fasciatum × Male Leiarius marmoratus,Subjected to Different Slaughter Methods

The objective of this study was to check the effect of different stunning methods on the meat quality of Pintado Amazônico, female Pseudoplatystoma fasciatum × male Leiarius marmoratus, stored on ice for 18 d. A total of 90 specimens (2.5 ± 0.45 kg and 58.21 ± 6.20 cm) were divided into three groups and subjected to stunning by: water saturated with CO₂, hypothermia on ice, or asphyxia in air. Subsequently, samples were removed to be analyzed after (times) 0, 2, 4, 6, 8, 10, 12, 14, 16, and 18 d. At the established times, aerobic mesophilic heterotrophic microorganisms and aerobic psychrotrophic heterotrophic microorganisms were quantified, and the pH, total volatile base nitrogen, color (L*a*b*), and sensory traits were analyzed. The stunning method significantly affected (P < 0.05) the meat quality. The group stunned on ice showed the best results compared with the other treatments.     

Effect of Freeze-Chilled Treatment on Flavor of Grass Carp (Ctenopharyngodon idellus) Fillets and Soups During Short-Term Storage

ABSTRACT

In order to evaluate the effect of chilled (T1), frozen (T2), and freeze-chilled (T3) treatment on the flavor of grass carp fillets and soups, adenosine triphosphate (ATP)-related compounds, umami-taste amino acids (UTAA), thiobarbituric acid (TBA), peroxide value (PV), and soup sensory score were analyzed. Results showed that the sum of ATP, ADP, and AMP contents in T2 fillets were significantly higher (p < 0.05) than others, but the sum of hypoxanthine riboside (HxR) and hypoxanthine (Hx) contents for T2 fillets and soups were significantly lower (p < 0.05) than others during storage. The T3 fillets and soups had lower inosine 5-monophosphate (IMP) contents than T1 after Day 2, but higher UTAA contents than T1 during storage. The T3 fillets had the highest TBA and PV values among the three groups during storage. According to the total aerobic counts, K value, and sensory score, all the fillets and soups kept good quality during storage. Therefore, freeze-chilled treatment not only can extend fish shelf life but also retain excellent fish flavor.     

Formation of Biogenic Amines and Associated Biochemical and Microbial Attributes of Whole Sutchi Catfish (Pangasianodon hypophthalmus) during Iced Storage

Sutchi catfish (Pangasianodon hypophthalmus) is a highly preferred farmed species that is produced in huge quantities. Meat from ice-stored (4 ± 2°C) whole Sutchi catfish was evaluated for formation of biogenic amines, such as putrescine, cadaverine, histamine (HIM), agmatine, tyramine, spermine, and spermidine, and compared with biochemical, microbial, and sensory attributes during 22 days. Analysis of content of biogenic amines in the meat was carried out by liquid chromatography with tandem mass spectrometry using a without derivatization method. Three amines, namely, tyramine, spermidine, and spermine, were only present on 0^th day of storage. Presence of cadaverine was noticed from 9^th day onwards, where the aerobic plate count (APC) reached 4.85 log CFU/g. Putrescine was detected on the 22^nd day of storage, where the APC crossed 7 log CFU/g. HIM was detected in lower quantities from 3^rd day onwards. A shelf life of 15 days was determined based on sensory and microbiological evaluation. Although the samples were biochemically acceptable throughout the storage period, APC exceeded the limit on day 19, and the gradual increase of H₂S-producing bacteria, Brochothrix thermosphacta, Aeromonas, and Enterobacteriaceae, was observed during storage.     

Effect of CO2 on Chemical and Microbial Changes of Pacific White Shrimp During Modified Atmosphere Packaging

ABSTRACT

This study monitored the physical, chemical, and sensory quality of raw Pacific white shrimp (Litopenaeus vannamei) and the evolution of microbial flora under modified atmosphere packaging (MAP) with varying concentrations of CO₂ (95% CO₂/5% O₂; 80% CO₂/15% N₂/5% O₂; 65% CO₂/30% N₂/5% O₂) at 4°C during 10-day storage. Plate counts on selective agars indicated that MAP had a strong inhibitory effect on psychrotrophic bacteria, mesophilic bacteria, Enterobacteriaceae, and H₂S-producing bacteria. Analyses with molecular techniques (denaturing gradient gel electrophoresis, DGGE) by extracting bacterial DNA from shrimp samples showed that Vibrio spp. and Aeromonas spp. were predominant in fresh MAP samples. Shewanella putrefaciens, which dominated in samples stored in air, were found sporadically in MAP samples. Interestingly, lactic acid bacteria were not predominant in MAP samples, whose pH values were high (6.66 to 8.14) during storage. The content of total volatile basic nitrogen in MAP samples was about 10 mg N/g lower than the control at the end of storage. Higher lightness values and sensory scores were also observed in samples under MAP. However, MAP with CO₂ concentrations higher than 80% did not enhance the inhibitory effect on bacterial growth but induced more severe reddening and sensory quality loss.     

Effect of in situ sediment remediation combining oyster shells and bottom microporous aeration on nitrogen removal and microbiota

The present intensive aquaculture results in an excessive accumulation of nutrient and organic residues in sediment. Then, pollutants accumulated in sediment would strongly affect water quality and increase the occurrence of pathogenic microorganisms. Thus, remediation of sediment is needed for removing excess nutrient and preventing aquatic animal diseases. In the present research, sediment in cement tanks was remediated with a combined method: crushed oyster shells (OS) and bottom microporous aeration (MA) treatment. The experiment included the control group (CK), treatment 1 (bottom MA), treatment 2 (crushed OS), and treatment 3 (bottom MA and crushed OS, MA+OS). The experimental results showed that from the second week after the experiment began, the organic matter (OM) content in the sediment from MA+OS was lower than that of the CK. From the eighth week, the total nitrogen (TN) and ammonia nitrogen (NH₄‐N) levels in the sediment from MA+OS were lower than those of CK, and the remediation experiments on sediment had little effect on the water quality in the experimental groups. Functional bacteria in the water column, including the families Erythrobacteraceae and Microbacteriaceae and the genera Phenylobacterium and Beggiatoa, were elevated in MA+OS. Thus, crushed OS and bottom aeration could promote nitrification in water, reducing the levels of OM, (NH₄‐N), and TN in sediment, through affecting the microbiota in the water column and promoting nutrient circulation, and could improve the overall benthic environment. The method has been demonstrated to be easy and effective for nitrogen removal from sediment.     

Effect of electrical stunning at slaughter on the carcass, flesh and eating quality of farmed sea bass (Dicentrarchus labrax)

Food quality aspects of farmed sea bass (Dicentrarchus labrax) were compared following two methods of slaughter: the normal commercial method of killing, by immersion in an ice slurry, or by first electrically stunning the fish, before immersion in an ice slurry. Quality was assessed for up to 10 days of storage on ice after slaughter. No differences were found between the slaughter methods in terms of an overall sensory evaluation of cooked fillets, or in terms of overall carcass quality: overall appearance, internal and external haemorrhage, fin damage, burst gall bladder, staining of the body cavity by leakage from the gut or damage to the spine. Using objective measurements of colour, no differences between fish from either treatment were found in terms of external colour or colour of the fillets. A chemical analysis of flesh nucleotide breakdown products as well as the freshness indicator K_i value did not differentiate the two treatments nor did the industry standard freshness scoring technique (QIM, quality index method), over 10 days of storage on ice. Flesh pH was marginally lower in electrically stunned fish at 4 h post mortem (6.42 cf 6.56) but by 24 h, pH in fish from both treatments had decreased to a similar level (6.22). Humane electrical stunning of sea bass at slaughter neither measurably improved nor decreased product quality for between 1 and 10 days of storage on ice. Electrical stunning accelerated the pattern of onset and resolution of rigor mortis. If electrical stunning were to be widely adopted, re‐education of buyers would be necessary as rigor mortis is currently used by buyers as a proxy measure of fish freshness.     

Chemical Parameters for Traceability of Raw Material Freshness of Tropical Surimi

ABSTRACT

Changes in chemical parameters of tropical fish used for surimi production—namely, threadfin bream (TB; Nemipterus spp.), lizardfish (LZ; Saurida spp.), and goatfish (GF; Upeneus spp.)—during ice storage and their respective washed mince were investigated. Total volatile basic nitrogen (TVB-N), trimethylamine (TMA), hypoxanthine (Hx), and total biogenic amine (BA) content of mince increased with storage time. Crude protein of fish and their respective washed mince reduced as storage time of fish was prolonged. Principal component analysis (PCA) revealed that washed mince produced from fish stored in ice for 7–12 days showed chemical characteristics that were distinct from those of washed mince prepared from spoiled fish. The TMA, TVB-N, and Hx content of washed mince appeared to be sufficient raw material freshness indicators in these three species.     

Effects of Partial and Complete Replacement of Synthetic Cryoprotectant with Carrot (Daucus carota) Concentrated Protein on Stability of Frozen Surimi

ABSTRACT

The study aimed to evaluate the effects of carrot concentrated protein (CCP) as additive on the functional and textural properties of surimi from striped catfish (Pangasianodon hypophthalmus) during six months of frozen storage (?20°C). The CCP (82.22% crude protein) was used as an additive either a lone or with a synthetic cryoprotectant (sucrose-sorbitol-sodium tri-polyphosphate). Control was made with synthetic cryoprotectant only. Molecular weight of CCP was found to be 36 kDa. After six months, the results revealed that up to 50% of synthetic cryoprotectants could be replaced by CCP during frozen storage of surimi. Biochemical parameters such as protein solubility, Ca²⁺ATPase activity, and gel strength decreased significantly (p < .05) during storage. Treatment T-3 (CCP 0.5% + 50% of synthetic cryoprotectant) maintained quality of protein significantly superior (p < .05) in respect to denaturation and other functional and sensory attributes compared to all the treatments. The microstructure images of surimi confirmed that addition of CCP modified the ice crystal growth during frozen storage. This study suggests that CCP can be a potential additive to protect protein from denaturation along with partial replacement of chemical cryoprotectants.     

The obvious heterosis and genetic characters of intergeneric cross and backcross juveniles between blunt snout bream (Megalobrama amblycephala) and topmouth culter (Culter alburnus)

In this study, we used artificial insemination to generate hybrid groups of fish [MC‐F₁(MA♀×CA♂) and MC‐F₂(MC‐F₁♀×♂)] by intergeneric crosses of Megalobrama amblycephala (MA) and Culter alburnus (CA); sequential backcrosses [CAM‐B₁ (CA♀×MC‐F₁♂) and MCC‐B₁ (MC‐F₁♀×CA♂)] were also performed. All these hybrids showed high rates of fertilization, hatching and survival (p > 0.05). For genetic traits, compared with those of the M. amblycephala and C. alburnus parental lines (Table 1), the fertilization rate, hatching rate and 7‐day survival rate of MC‐F1(MA♀×CA♂), MC‐F2(MC‐F1♀×♂), CAM‐B1 (CA♀×MC‐F1♂) and MCC‐B1 (MC‐F1♀×CA♂) by artificial insemination exhibited similar high rates (p > 0.05). The morphology of the four hybrids MC‐F₁/F_2, CAM‐B₁ and MCC‐B₁ were intermediate between those of their parents. Compared with their parents of MA and CA, weight gain rate (WG), specific growth rate (SGR) and protein efficiency ratio (PER) of hybrids MC‐F₁/F₂, CAM‐B₁ and MCC‐B₁ were significantly (p < 0.05) increased and feed conversion ratio (FCR) was significantly (p < 0.05) decreased after 3 months feeding. Moreover, protein content of muscle for MC‐F₁/F₂, CAM‐B₁ and MCC‐B₁ was significantly (p < 0.05) higher and carbohydrate content of muscle was significantly (p < 0.05) lower than their parents. The females and males of the four hybrids had normal gonadal development. In this study, we successfully generated intergeneric and backcross hybridization lines with fertile potential among fish of the Cultrinae subfamily and these hybrids had obvious heterosis in terms of growth performance, feed utilization and muscle quality.     

Slaughtering method and dietary α-tocopheryl acetate supplementation affect rigor mortis and fillet shelf-life of turbot Scophthalmus maximus L.

The effects of dietary α‐tocopheryl acetate supplementation and different slaughtering methods were investigated on the flesh quality of farmed market‐size turbot Scophthalmus maximus (L). Turbot were divided into three groups and fed commercial diets, supplemented with different levels of α‐tocopheryl acetate at the following dietary inclusion levels: 72 (100), 547 (500), 969 (1000) (mg of α‐tocopheryl acetate kg^?1 diet, analytical values with diet codes in brackets). After 5 months, fish (mean weight 1056 ± 19.7 g) from each dietary treatment were sampled, applying three different slaughtering methods: (A) bleeding in ice water; (B) thermal shock, no bleeding; (C) percussion followed by bleeding in ice water. The time course of rigor mortis was evaluated, using pH, rigor index and mechanical compression tests. The results showed that the three parameters corresponded very well. Percussive stunning resulted in higher initial post‐mortem pH (P < 0.01) and a significantly delayed onset of rigor mortis (P < 0.05). Diet significantly affected shelf‐life, with fillets from fish fed diets 500 and 1000 having lower TBARS (thiobarbituric acid reactive substances) numbers from day 2 (P < 0.001) and less colour deterioration from day 7 of storage on ice onwards (P < 0.05). These results suggest that an increase in dietary α‐tocopheryl acetate before slaughter as well as careful selection of the slaughtering method may greatly enhance the flesh quality of market‐size turbot.     

Effects of Modified Atmospheric Packaging Conditions on the Quality Changes of Pasteurized Oyster (Crassostrea belcheri) Meat during Chilled Storage

ABSTRACT

The effects of different atmospheric conditions on the quality and the shelf life of pasteurized oyster meat in chilled storage were investigated. The alternatives tested for pasteurized oyster meat were normal air (Control), 75% CO₂/25% N₂ (MAP-1), 75% CO₂/25% O₂ (MAP-2), 75% CO₂/5% O₂/20% N₂ (MAP-3), and vacuum packing (VP). The various observations of microbiological (total viable count (TVC), Enterobacteriaceae, Pseudomonas spp., lactic acid bacteria (LAB), and hydrogen sulfide–producing bacteria), physical (color coordinates L*, a*, and b*, and cutting strength), chemical (moisture, pH, total volatile basic nitrogen (TVB-N), peroxide value (PV), and thiobarbituric acid reactive substances (TBARS)) and sensory properties were performed every 3 days over a total of 27 days. During storage across all the treatments, L*, a*, cutting strength, pH, moisture content, and sensory scores decreased; whereas, b*, TVB-N, PV, TBARS, and microorganisms increased. However, among the various alternatives, MAP-1 had the best retention of oyster quality during storage. Based on sensory and microbiological qualities, the shelf lives in chilled storage were 9 days for control, 15 days for VP, 21 days for MAP-2 and MAP-3, and 24 days for MAP-1-treated cases.     

Microbiological and Physicochemical Quality of Carp sausage Enriched With Propolis Natural Extract during Chilled Storage

This study aimed to determine the effect of propolis extract on quality of liquid smoked carp (Cyprinus carpio) sausage stored at 2°C for 9 weeks. Carp sausages were separated into three groups: control group, without propolis extract; second group, with 1% (w/w) propolis extract added; and third group, with 2% (w/w) propolis extract added. Propolis extract added carp sausages showed lower total volatile basic nitrogen (TVB-N) value, peroxide value (PV), and free fatty acid (FFA) content compared to control during the storage period. During 9 weeks of storage, propolis extract added carp sausages showed significantly lower total aerobic mesophilic bacteria (TAMB) and psychrophilic bacteria count (PBC) than those of control samples (p < .05). Yeast and mold were not detected in all fish sausages throughout the storage period.     

模拟探究凡纳滨对虾磷脂在贮藏过程中的水解机理

为探究凡纳滨对虾磷脂(PL)在贮藏过程中的水解机理,本研究建立了磷脂相关酶与磷脂酰胆碱(PC)的体外模型,模拟凡纳滨对虾磷脂水解反应。实验分别从凡纳滨对虾体内分离纯化得到磷脂相关酶与PC,进行体外反应,并采用"鸟枪"脂质组学法及气相色谱—质谱法分析水解反应前后PC、溶血磷脂(LPL)及游离脂肪酸(FFA)的组成和含量变化,进而推断磷脂的水解机理。结果显示,凡纳滨对虾体内磷脂水解酶包括脂肪酶、磷脂酶A_1(PLA_1)、磷脂酶A_2(PLA_2)、磷脂酶C(PLC)及磷脂酶D(PLD),其中PLA2活力最高,可达177.87 U。体外模拟反应中,凡纳滨对虾PC含量由516.45显著降至146.14 mg/g,总FFA含量由36.42上升至568.57 mg/g,其中多不饱和脂肪酸(PUFA)显著增加了280.5 mg/g。通过相关性分析水解前后磷脂水解酶活力变化与PC含量变化,发现PC的变化与PLA2显著相关(R=0.91)。研究表明水产品中PC变化是磷脂相关酶催化的水解反应,其水解产物主要为FFA与LPC,且PLA_2对水产品贮藏过程中磷脂的水解影响最大。本实验建立了新型的体外水解模型,并初步探究了磷脂的水解机理,为水产品贮藏及磷脂酶的研究及应用奠定了理论基础。     

Characterization of the pelagic ecosystem in surface waters of the northern Gulf of St, Lawrence in early summer: the larval redfish-Calanus-microplankton interaction

In June 1989, the water column along a transect in the north-central Gulf of St Lawrence was thermally stratified (10–14^oC at the surface; 0-l^oC at 30 m). In the surface layer, nitrate and chlorophyll concentrations were very low; the mean concentration of chlorophyll a > 5 μm in the subsurface maximum was 0.26 μg1^-1. Autotrophic and (presumably) heterotrophic flagellates and dinoflagellates were the most abundant micro-plankton. In this system, redfish (Sebastes spp.) larvae and the planktonic copepod Calanus finmarchicus overwhelmingly dominated the ichthyoplankton and zoo-plankton, respectively. Redfish larvae, Calanus females and Calanus eggs were most abundant in the surface layer (0–25 m) day and night. Daily specific egg production rates of Calanus, calculated from shipboard incubations of females, approached the predicted maximal level for this species at the ambient temperature of the surface layer, indicating no or little food limitation. The redfish larvae were feeding almost exclusively on the Calanus eggs and were found in greatest abundance along the transect where Calanus egg production rates (eggs m^-2 day^-1), calculated from the product of the specific egg production rate and female concentration, were highest. The mono-specificity of the larval redfish diet and the codom-