Ref. Ares(2019)2387732 - 04/04/2019
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TABLE OF CONTENTS
1. INTRODUCTION AND BACKGROUND ........................................................................................ 4
2. OBJECTIVES ................................................................................................................................ 6
3. MATERIAL AND METHODS ........................................................................................................ 7
3.1 On-board survival experiment ................................................................................................ 7
3.1.1 Vessel ................................................................................................................................... 7
3.1.2 Hauls and captures ............................................................................................................... 7
3.1.3 Recovery in tanks ................................................................................................................. 8
3.1.4 Survival ................................................................................................................................. 8
3.2 Experiment on-land to know physiological recovery times .................................................... 8
3.2.1 Experimental conditions ...................................................................................................... 8
3.2.2 Sampling ............................................................................................................................... 9
3.3 Analysis of physiological responses to stress after commercial capture .............................. 10
3.4 Variables analyzed ................................................................................................................. 10
3.5 Statistics ................................................................................................................................ 11
4. RESULTS AND DISCUSSION ...................................................................................................... 12
4.1 Survival rates on-board ......................................................................................................... 12
4.2. Evaluation of physiological recovery at the laboratory ....................................................... 13
4.2.1 Cortisol ............................................................................................................................... 13
4.2.2 Energy metabolites and osmoregulatory parameters ....................................................... 14
4.2.3 Mortality at the laboratory ................................................................................................ 16
4.3. Evaluation of physiological recovery after fishing ............................................................... 17
4.3.1 Cortisol ............................................................................................................................... 17
4.3.2 Energy metabolites and osmoregulatory parameters ....................................................... 18
5. CONCLUSIONS ......................................................................................................................... 19
6. REFERENCES ............................................................................................................................ 20
2
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TABLE OF FIGURES
Figure 1. Red sea bream (Pagellus bogaraveo). ............................................................................ 4
Figure 2. Concrete blocks used to set up the fishing gear called "Voracera", and lines of baited
hooks fastened to the blocks. ....................................................................................................... 4
Figure 3. Plasma cortisol in Pagellus bogaraveo subjected to persecution (similar stress as that
suffered by the fishing with a hook) for 10 minutes, with recovery afterwards and sampling at 0,
5 and 24 h after stress. Black bars indicate the stressed group, and gray bars indicate the control
group. Different letters indicate significant differences between times for the stressed group;
while the asterisk (*) indicates differences between the control group and the stressed group
for a specific time (p <0.05, two-way ANOVA followed by the Tukey’s test). ............................ 14
Figure 4. Plasma cortisol in Pagellus bogaraveo caught in the Strait of Gibraltar through the art
of fishing "voracera". Samples taken just after the fishing (0 h) and after 5 hours of recovery in
tanks on board (5 h). The asterisk (*) indicates significant differences between the two sampling
times (p<0.05, Student’s t for paired samples). .......................................................................... 17
TABLE INDEX
Table 1. Plasma glucose, lactate, triglycerides (TAG), proteins and osmolality in Pagellus
bogaraveo subjected to persecution (similar stress as that suffered by the fishing with a hook)
for 10 minutes, with recovery afterwards and sampling at 0, 5 and 24 h after stress. Different
letters indicate significant defferences between the control group and the stressed group for a
specific time (p <0.05, two-way ANOVA followed by the Tukey’s test). ..................................... 15
Table 2. Plasma glucose, lactate, triglycerides (TAG), proteins and osmolality in Pagellus
bogaraveo caught in the Strait of Gibraltar through the fishing gear of "Voracera". Samples taken
after fishing (0 h) and 5 hours after recovery in tanks on board. The asterisk (*) indicates
significat differences between the sampling times (p<0.05, Student’s t for paired samples).... 18
3
1. INTRODUCTION AND BACKGROUND
In line with the new Common Fisheries Policy and, according to the Article 15 of
Regulation 1380/2013 / EU, discards from European fisheries shall be landed. However,
as it appears at Article 15 (paragraph 4b), species whose scientific evaluation indicates
high survival rates and complete recovery after the fishing process, may be returned to
the sea.
The red sea bream (
Pagellus bogaraveo, figure 1) is exploited in the area of the Strait of
Gibraltar by an artisanal fleet based in the port of Tarifa and, in a lesser extent, in
Algeciras and Ceuta. This species is caught with a specific hook art called "voracera",
which is set with the help of a stone or block of concrete (figure 2) and remains in the
water arround 15 to 30 minutes.
Figure 1. Red sea bream (Pagellus bogaraveo).
Figure 2. Concrete blocks used to set up the fishing gear called "Voracera", and lines of baited hooks
fastened to the blocks.
4
The current legislation contemplates a mínimum first capture size of 33 cm, but smaller
specimens under this size are usually captured. The main objective of the present study
has been to evaluate the survival capacity of these specimens after have been fished
with the "voracera" in the Strait of Gibraltar.
In order to evaluate the survival capacity of a species, an approach to its capacity of
recovery from the fishing process is needed. It has been demonstrated that fishing is a
stress process for fish (Olsen et al., 2012). The responses to stress in these organisms
can be classified into primary, secondary and tertiary responses (Barton, 2002).
Primary response include the activation of the sympathetic nervous system, releasing
catecholamine hormones from the chromaffin tissue (Reid et al., 1998), and the
stimulation of the interrenal axis, which releases corticosteroid hormones (cortisol in
teleost) to the circulatory system (Wendelaar Bonga, 1997).
The secondary response is defined as those actions produced by these hormones
(Mommsen et al., 1999), summarized in the release of energy metabolites to plasma,
increase in respiratory rate to favor the availability of oxygen, and increase in heart rate
to mobilize these substrates throughout the body.
The tertiary response extends to the organism and population level (Wedemeyer et al.,
1990), affecting the performance of the animal (growth, reproduction and behaviour),
and being able even to lead to the death of the individual.
The recovery process after a stressful situation includes regain homeostasis body level,
either by returning to basal state or by establishment of an allostatic condition (McEwen
and Wingfield, 2003; Costas et al., 2011).
There have been numerous studies of stress responses in teleost fish (Iwama, 1998; Flik
et al., 2006). Within the main metabolites released as result of secondary response,
glucose and lactate are good indicators of stress in fish (Arjona et al., 2007).
In stress situations, the mobilization of glucose through the circulatory system facilitates
its immediate use by those tissues that need an extra energy contribution.
5
On the other hand, lactate is considered a metabolic by-product of glycolysis during high
energetic expenditure situations, where it occurs a state of hypoxia (Gladden, 2004).
The time required for a species to show signs of recovery varies according to the stressful
agent, the environmental conditions and / or the size of the individual. In previous
studies made with teleosts like gilt-head sea bream (
Sparus aurata) or sole (
Solea
senegalensis) has been seen that secondary responses to a situation of acute stress
return to baseline values between 4 and 6 hours after the stressful situation (Laiz-
Carrion et al., 2005, Costas et al., 2011).
Therefore, acute stress as may be the fishing process,
a priori will have an impact on the
red sea bream (member of the sparid’s family, such as the gilt-head sea bream) during
the first 4-6 hours after its liberation.
If there are no signs of recovery after that time (normal movements and basal values of
stress indicators in plasma), is likely that the limits of animal tolerance have been
exceeded and the recovery could be endangered.
2. OBJECTIVES
Evaluate the survival capacity of non-commercial sizes (<33 cm in total length) of the red
sea bream (
Pagellus bogaraveo) after artisanal hook fishing in the Strait of Gibraltar.
This Main Objective contemplates two Specific Objectives:
1. Evaluation of the survival rates of individuals captured by commercial
fisheries boats.
2. Analysis of physiological responses to stress caused by fishing to evaluate the
recovery capacity of the captured animals.
6
3. MATERIAL AND METHODS
Three experiments were carried out: i) survival experiment on-board; ii) experiment to
know the times of physiological recovery on-land; and iii) analysis of physiological
responses to stress after commercial capture.
The inland experiment validate the results of the on board experience, allowing a
temporary follow-up under controlled conditions.
3.1 On-board survival experiment
3.1.1 Vessel
A red sea bream capture campaign was carried out aboard the commercial ship "
"(number plate
with base port in Tarifa (Cádiz, Spain). This boat
was chartered in 2010, it has
m length,
and a capacity for 5
crewmen. The shipping dates were on 7th, 8th, 10th and 13th of November 2017.
A total of 14 hauls of “voracera” (between 3 and 5 hauls per day) were made on the
fishing grounds of "Bad stones" (latitude 35-36º 54-56 ', longitude 05º 48-49') and
"Discoteca" (latitude 35-36º 55-56 ', longitude 05º 50-51') of the Strait of Gibraltar. The
range of depths was from 128 to 247 m.
The time of permanence of the art in the water varied between 20 and 35 minutes, with
an average of 10 minutes since the concrete block reached the bottom and the art were
raised up to the surface. On the ship there were 4 tanks of more than 2000 L, which
were pumped continuously with water from the surface of the sea.
3.1.2 Hauls and captures
12 valids hauls were made, in which a total of 102 red sea bream with a size below the
commercial minimum (29.4 ± 0.2 cm total length, mean ± SEM, and a calculated weight
of 378 ± 7 g).
7
To calculate the wet weight (in grams) of the animals was taken into account the total
length (in centimeters) according to the Von-Bertalanffy equation, assuming the values
of: a = 0.008 and b = 3.178. These values were obtained by the Spanish Oceanography
Institute (IEO), in its headquarters in Cádiz (Spain), after years of studying the natural
populations of this species.
3.1.3 Recovery in tanks
Of the 102 red sea bream captured, 66 were used for the survival experiment on-board.
It was calculated an average time of 10 minutes since the art reached the bottom until
the fish were hoisted on board.
Once they were embarked, the animals were immediately marked individually with a
rubber label placed on the caudal peduncle and they were released into the recovery
tanks.
The whole process lasted less than 30 seconds per animal, time from its release into the
air until its release in the tanks. A single tank was used per haul, and the number of
animals varied between 1 and 24 animals, with an average of 7 animals per haul.
3.1.4 Survival
The animals were kept in tanks for 5 hours, and the individuals deceased after that time
were counted. The survival percentage was calculated for each set.
3.2 Experiment on-land to know physiological recovery times
3.2.1 Experimental conditions
To check out if the animals recover internal metabolic homeostasis after fishing, and to
consider that they have recovered completely, an experiment was carried out under
controlled conditions at the laboratory.
8
The experiment was carried out in the facilities of marine cultures of the IEO from Vigo
(Spain), with red sea bream cultivated in captivity of almost 4 years old. 54 red sea
breams of 25.3 ± 0.2 cm of total length, 23.5 ± 0.2 cm of fork length and 270.6 ± 6.0 g of
wet weight (values represented as mean ± SEM) were used.
These animals were randomly distributed into groups of 3 animals, they were located in
18 flat-bottomed cubic tanks of 400L of capacity, and they were kept in open circuit
regime for two weeks for its acclimatization.
The daily feeding was done with commercial feed and the cleaning and maintenance of
the tanks were limited thus not to cause an additional stress to the fishes. The animals
fasted 24 h before the experiment starts. The tanks were numbered randomly and
divided into two groups: one control, and another experimental. The experimental
treatment consisted in emulating the fishing process of the "voracera". For this purpose,
a chase of the animals was carried out inside the tanks with hand nets for 10 minutes,
estimated time of stay on the hook during commercial fishing.
This procedure has been previously tested by other research groups (Gesto et al., 2015)
and is useful for assessing the level of stress and exhaustion in bone fish. The samples
were taken at 0h, 5h and 24h after the stress process. 3 tanks were used for each
experimental group and time. The time of 5 h was selected because the gilt-head sea
bream, a member of the same family as the red sea bream, presents an appreciable
recovery in its plasma levels of cortisol and energy metabolites 4 h after acute stress
(Laiz-Carrion et al., 2005).
3.2.2 Sampling
For sampling, all 3 animals from the same tank were captured by hand nets at the same
time and immediately transferred to a supplementary tank with 100 L of seawater and
2-phenoxyethanol at a concentration of 0.5 mL /L seawater (0.05%, v / v). After
anesthesia, the animals were weighed and measured and a blood sample was extracted
from the caudal peduncle with heparinized syringes.
9
After this process, the animals were returned to their original tanks in less than 4
minutes since its capture. The blood was centrifuged at 10000 g during 3 minutes at 4 °
C and the plasma was separated and frozen at -80 ° C until analysis. Almost all animals
were recovered after the experiment, but a total of 6 individuals died in the process of
recovery after sampling. It should be noted that 4 of the animals that died belonged to
the control group, while the other 2 belonged to the group stressed, but from the times
5 h and 24 h post-stress.
3.3 Analysis of physiological responses to stress after commercial capture
On board the ship used for the survival experiment an analysis of physiological
responses after fishing was made.
For this test, 36 animals from 7 different hauls were selected (varying between 2 and 7
animals per set, with an average of 5 animals per haul) which were marked individually
with rubber bands in the caudal peduncle, and sampled immediately after capture (10
minutes of fight on the hook followed by 15 seconds of exposure to the air).
200 microliters of blood were taken from the caudal peduncle with heparinized syringes
and the animals were released in 2000 L tanks for recovery.
A recovery tank was used for each haul. After 5 h, the animals were immediately
captured using hand nets, wrapped in a damp cloth to avoid additional stress, and a new
sample of 200 microliters of blood from the caudal peduncule was taken. The Individual
marking allows to correlate the blood samples from 0 h to 5 h after fishing and recovery.
The tubes with blood were centrifuged at 10000 g for 3 minutes at 4 ° C. The plasma was
separated and frozen in liquid nitrogen and then stored at -80 ° C.
3.4 Variables analyzed
From blood plasma taken during the on-land on-board experiments cortisol, glucose,
lactate, triglycerides, proteins and osmolality were analyzed, being these the main
biomarkers of acute stress in bone fish.
10
Cortisol was analyzed using a commercial kit (Arbor Assay, MI, USA). Glucose, lactate
and triglycerides were analyzed by commercial kits (Spinreact SA, Girona, Spain), as well
as total proteins (Pierce BCA Protein Assay Kit, Thermo Scientific, IL, USA).
The osmolality was measured by a vapor pressure osmometer (Vapro 5520 Osmometer,
Wescor, USA). All analyzes except osmolality were performed using a microplate reader
(Bio-Tek Instruments, Winooski, VT, USA), and using the KCJunior Data Analysis program
for Microsoft Windows XP.
3.5 Statistics
Normality and homoscedasticity were analyzed by the Shapiro-Wilk’s and Levene’s
tests, respectively. The differences between groups for the physiological experiment on-
land were calculated by means of a two-way ANOVA with the group (control and stress)
and the time (0, 5 and 24 h) as variance factors.
For the experiment of physiological recovery of the boat the differences between groups
were calculated by a repeated measures ANOVA with the haul number and the time (0
and 5 h) as variance factors. Logarithmic transformations of the data were made when
it was necessary to meet the requirements of the ANOVA.
When the ANOVA results showed significant differences, the Tukey’s test was used as
a
posteriori test.
The Student’s t-test for paired samples was used to evaluate the differences between
the physiological parameters of the experiment done on-board once it was established
that the factor haul did not affect the dependent variables analyzed. Statistical
significance was established in p <0.05. All results are shown as mean ± SEM.
11
4. RESULTS AND DISCUSSION
4.1 Survival rates on-board
The survival rates of the two on-board experiments were calculated. As there were no
significant differences between the survivals of the groups captured in each haul (p
<0.05, Student’s t), we proceeded to unify the groups of each haul, constituting
duplicates of the same sample (haul). Therefore, it made a total of 12 valid hauls during
a 4-day campaign in the Strait of Gibraltar, with 102 animals captured.
The result of this study shows a figure of survival of 90.6 ± 6.2% after 5 h of recovery in
on-board tanks. If we have in mind that the animals evaluated were in similar conditions,
but not accurate, to those of the natural environment, this figure could be even higher
in case of direct release to the ocean.
Although other factors should be taken into account, such as post-capture predation.
However, the figures are very similar to those calculated in other discarded species such
as the small-spotted catshark (
Scyliorhinus canicula) captured by bottom trawling (Revill
et al., 2005), being one of the species considered more resistant from the spanish south-
Atlantic area (Barragán-Méndez, Ruiz-Jarabo et al., Article sent for publication).
Although survival rates were greater than 90%, it is important to confirm if the animals
truly reach the recover after the recovery period or not.
Through a physiological approach can be established if the red sea bream captured
arrived in exhaustion conditions until the no return point.
Therefore, to know the animals state after capture, and after recovery time is essential
to be able to support the hypothesis that the red sea bream which remains alive after
the capture would survive if they were released to the environment.
12
4.2. Evaluation of physiological recovery at the laboratory
4.2.1 Cortisol
Plasma cortisol is the main glucocorticoid of teleost fishes (Mommsen et al., 1999). The
increase of it in the red sea bream subjected to a process of acute stress like the fishing
process (figure 3) is necessary to mobilize energy reserves during the first moments.
Our results at the laboratory coincide with those of other fishes such as gilthead
seabream (
S. aurata) or sole (
S. senegalensis) subjected to acute stress (Laiz-Carrion et
al., 2005; Costas et al., 2011).
Although there is no significant differences in the stressed group between 0 and 5h, a
decrease of a third part of the concentration of cortisol happened between one time
and another.
In such a way, we can say that a period of 5 hours is enough for the red sea bream (
P.
bogaraveo) to start showing signs of recovery at the level of primary markers of stress.
It worth to pointing out the high concentrations of cortisol present in plasma of animals
from the control group (40.2 ± 7.7 ng Cortisol mL-1).
Previous studies show that plasma cortisol in teleost fish in basal conditions oscillate
around 20 ng mL-1 (Ellis et al., 2012; Louison et al., 2017), although there may be
variations depending on the kind of analysis, the species studied, the population or the
time of year.
13
250
Estrés
Control
*
A
200
)
-1
*
mL
A
g 150
(n
l
**Translation: Estrés = Stress,
iso 100
tiempo = time.
Cort
B
50
0
0
5
24
Tiempo (h)
Figure 3. Plasma cortisol in Pagellus bogaraveo subjected to persecution (similar stress as that suffered
by the fishing with a hook) for 10 minutes, with recovery afterwards and sampling at 0, 5 and 24 h after
stress. Black bars indicate the stressed group, and gray bars indicate the control group. Different letters
indicate significant differences between times for the stressed group; while the asterisk (*) indicates
differences between the control group and the stressed group for a specific time (p <0.05, two-way
ANOVA followed by the Tukey’s test).
Black columns indicate stressed group, grey ones control group.
4.2.2 Energy metabolites and osmoregulatory parameters
The stress caused by the fishing simulation causes the release of energy reserves to the
blood (Table 1). After a stressful situation, typical secondary responses promoted by that
hormones release (such as cortisol) include mobilisation of glucose and, under anaerobic
conditions, the appearance of lactate. These responses described coincide with our
results. In time 0 h after stress, the red sea bream begins to release glucose to the blood,
which shows its maximum concentration at 5 h after the start of recovery.
This late increase (no noticeable 10 minutes after acute stress) matches what has been
described previously in the senegalese sole (Costas et al., 2011) and the small-spotted
catshark (Barragán-Méndez, Ruiz-Jarabo et al., Article sent for publication), and it may
be due to a very high glucose consumption in the first moments post-stress, preventing
the increase in the concentration of plasma glucose until the rate of metabolic
consumption decreases.
14
Nevertheless, the lactate concentration in the present study is significantly greater to
that in the control group after 10 minutes of pursuit, which indicates an immediate
activation of anaerobic metabolism in this species, in line with other teleosts (Frisch and
Anderson, 2005, Costas et al., 2011).
Proteins and triglycerides (TAG) do not seem to vary in the red sea bream subjected to
a process of acute stress, so it can be deduced that the main metabolites of consumption
at short term are others (glucose, for example).
Parameter
Group
0 h
5 h
24 h
Glucose
Stress
3.97 ± 0.26 B
5.54 ± 0.39 A*
4.26 ± 0.14 B
(mmol L-1)
Control
3.18 ± 0.15
3.19 ± 0.12
3.46 ± 0.09
Lactate
Stress
2.80 ± 0.46 A*
2.30 ± 0.32 A
1.06 ± 0.12 B
(mmol L-1)
Control
1.07 ± 0.08
1.40 ± 0.12
1.24 ± 0.08
TAG
Stress
0.79 ± 0.09
0.64 ± 0.08
0.65 ± 0.07
(mmol L-1)
Control
0.75 ± 0.04
1.01 ± 0.18
0.74 ± 0.12
Proteins
Stress
28.1 ± 1.0
23.6 ± 0.8
24.6 ± 1.5
(mg dL-1)
Control
27.5 ± 1.4
25.7 ± 0.8
27.5 ± 1.3
Osmolality
Stress
291 ± 3 A*
260 ± 2 B
257 ± 2 B
(mOsmol kg-1)
Control
264 ± 4
267 ± 1
263 ± 1
Table 1. Plasma glucose, lactate, triglycerides (TAG), proteins and osmolality in Pagellus bogaraveo
subjected to persecution (similar stress as that suffered by the fishing with a hook) for 10 minutes, with
recovery afterwards and sampling at 0, 5 and 24 h after stress. Different letters indicate significant
defferences between the control group and the stressed group for a specific time (p <0.05, two-way
ANOVA followed by the Tukey’s test).
Regarding changes in the osmoregulatory system, the present study shows an increase
in plasma osmolality in the group subjected to acute stress at time 0h (Table 1).
15
Due to the initial increase in energy expenditure produced by the process of stress, other
systems are harmed and suffer imbalances that, once finished the process, they return
to their basal state.
These kind of responses are normal in marine fish, osmoregulators, because they have
an internal fluids’ osmolality lower to that of the external environment. After a stressful
situation, a series of responses such as vasodilation of blood vessels increasing the
surface of contact between the blood and the external environment (hypertonic), which
lead to a passive dehydration of the animal (McCormick et al., 2013). Our results show
that the red sea bream is able to return to control levels after 5 h after acute stress.
4.2.3 Mortality at the laboratory
In the experiment carried out under controlled conditions, there was a certain mortality
rate in non-stressed animals (control) and in those recovered after a acute stress
situation.
The cause of this mortality can be the release of catecholamines and cortisol in the
chromaffin and interrenal tissue as described in sea bass (
Dicentrarchus labrax) (Rotllant
et al., 2006), causing heart failure in healthy animals and / or not exhausted.
The high levels of cortisol (Figure 3) found in this species seem support this hypothesis.
In this way, healthy animals that have not been subjected to physical fatigue during the
process of capture, can suffer a cardiac arrest. However, the red sea bream that have
exhausted a certain amount of energy fighting during its capture process (escaping from
a net or trying to free himself from a hook, for example) are more likely to survive than
those caught quickly.
16
4.3.2 Energy metabolites and osmoregulatory parameters
The results of the experiment on-board the commercial fishing vessel indicate a
physiological recovery of the animals after 5 h in the tanks (Table 2). The levels of glucose
at time 0 h of the ship coincide with the levels of the group stressed at 0 h of the
experiment on-land, although the glucose levels after 5 h on the ship are greater than
those on-land at the same time. This difference may be due to processes such as feeding
/ fasting of the red sea bream in both experiments.
The levels of lactate from both experiments (ship and land) coincide at times 0 h and 5
h respectively, which reinforces the idea that both experimental approaches are
comparable in terms of intensity and duration of the stress agent. Thus, we can talk
about a recovery process in the red sea bream captured after a fishing with "voracera".
Reinforcing this idea are the plasma osmolality data, which decreases in both
experiments after 5 h of recovery.
The GAT and protein results indicate plasma differences between wild animals and those
kept in captivity. In this way, the response of the first includes the mobilization of plasma
proteins after capture (0 h), while the red sea bream experiments on-land did not
include this response. These differences can be due to the different composition of the
diets of both groups, as well as to the fact that the captive animals were fasting 24 h
before the experiment, while the last ingestion of wild animals is unknown.
Table 2. Plasma glucose, lactate, triglycerides (TAG), proteins and osmolality in
Pagellus bogaraveo caught
in the Strait of Gibraltar through the fishing gear of "Voracera". Samples taken after fishing (0 h) and 5
hours after recovery in tanks on board. The asterisk (*) indicates significat differences between the
sampling times (
p<0.05, Student’s t for paired samples)
Glucose
Lactate
TAG
Proteins
Osmolality
Group
(mmol L-1)
(mmol L-1)
(mmol L-1)
(mg dL-1)
(mOsmol kg-1)
0 h
4.4 ± 0.1
3.2 ± 0.2
1.8 ± 0.2
26.7 ± 0.5
302 ± 3
5 h
8.8 ± 0.4 *
2.1 ± 0.2 *
1.6 ± 0.2
21.5 ± 0.4 * 291 ± 3 *
18
5. CONCLUSIONS
1) Red sea bream (
P. bogaraveo) with a total length smaller than 33 cm, caught in
the Strait of Gibraltar through the art of fishing called "voracera", present
survival rates of 90.6 ± 6.2%.
2) The surviving animals manage to recover their basal homeostatic levels, being
able to speak of an effective physiological recovery between 5 and 24 hours after
the capture.
3) This study was carried out during the month of November of the year 2017, in
certain environmental conditions (temperature, salinity, etc.), so that the
conclusions have to take into account this limitation. However the Strait of
Gibraltar does not have a great variation in these conditions throughout the year,
so a similar survival and recovery rates are expected during other periods,
although complementary studies should be carried out ensure.
19
6. REFERENCES
Addis, P., Secci, M., Locci, I., and Cau, A. C. 2012. Harvesting, handling practices and
processing of bluefin tuna captured in the trap fishery: possible effects on the flesh
quality. Collective Volume of Scientific Papers ICCAT, 67: 390-398.
Arjona, F. J., Vargas-Chacoff, L., Ruiz-Jarabo, I., Martin del Rio, M. P., and Mancera, J. M.
2007. Osmoregulatory response of Senegalese sole (
Solea senegalensis) to changes
in environmental salinity. Comp Biochem Physiol A Mol Integr Physiol, 148: 413-421.
Barton, B. A. 2002. Stress in fishes: a diversity of responses with particular reference to
changes in circulating corticosteroids. Integrative and Comparative Biology, 42: 517-
525.
Costas, B., Conceicao, L., Aragao, C., Martos, J. A., Ruiz-Jarabo, I., Mancera, J., and
Afonso, A. 2011. Physiological responses of Senegalese sole (
Solea senegalensis Kaup,
1858) after stress challenge: Effects on non-specific immune parameters, plasma free
amino acids and energy metabolism. Aquaculture, 316: 68-76.
Ellis, T., Yildiz, H. Y., Lopez-Olmeda, J., Spedicato, M. T., Tort, L., Overli, O., and Martins,
C. I. 2012. Cortisol and finfish welfare. Fish Physiol Biochem, 38: 163-188.
Frisch, A., and Anderson, T. 2005. Physiological stress responses of two species of coral
trout (
Plectropomus leopardus and
Plectropomus maculatus). Comp Biochem Physiol
A Mol Integr Physiol, 140: 317-327.
Gesto, M., Hernandez, J., Lopez-Patino, M. A., Soengas, J. L., and Miguez, J. M. 2015. Is
gill cortisol concentration a good acute stress indicator in fish? A study in rainbow
trout and zebrafish. Comp Biochem Physiol A Mol Integr Physiol, 188: 65-69.
Gladden, L. B. 2004. Lactate metabolism: a new paradigm for the third millennium. J
Physiol, 558: 5-30.
Laiz-Carrion, R., Guerreiro, P. M., Fuentes, J., Canario, A. V. M., Martin Del Rio, M. P.,
and Mancera, J. M. 2005. Branchial osmoregulatory response to salinity in the
gilthead sea bream,
Sparus auratus. Journal of Experimental Zoology Part A
Comparative Experimental Biology, 303A: 563-576.
Louison, M. J., Adhikari, S., Stein, J. A., and Suski, C. D. 2017. Hormonal responsiveness
to stress is negatively associated with vulnerability to angling capture in fish. J Exp
Biol, 220: 2529-2535.
20
McCormick, S. D., Farrell, A. P., and Brauner, C. J. 2013. Euryhaline fishes
, Academic
Press, Oxford, UK.
McEwen, B. S., and Wingfield, J. C. 2003. The concept of allostasis in biology and
biomedicine. Hormones and Behavior, 43: 2-15.
Methling, C., Skov, P. V., and Madsen, N. 2017. Reflex impairment, physiological stress,
and discard mortality of European plaice
Pleuronectes platessa in an otter trawl
fishery. ICES (International Council for the Exploration of the Sea) Journal of Marine
Science, 496: 207-218.
Mommsen, T. P., Vijayan, M. M., and Moon, T. W. 1999. Cortisol in teleosts: dynamics,
mechanisms of action, and metabolic regulation. Reviews in Fish Biology and
Fisheries, 9: 211-268.
Olsen, R. E., Oppedal, F., Tenningen, M., and Vold, A. 2012. Physiological response and
mortality caused by scale loss in Atlantic herring. Fisheries Research, 129: 21-27.
Reid, S. G., Bernier, N. J., and Perry, S. F. 1998. The adrenergic stress response in fish:
control of catecholamine storage and release. Comparative Biochemistry and
Physiology C, 120: 1-27.
Revill, A. S., Dulvy, N. K., and Holst, R. 2005. The survival of discarded lesser-spotted
dogfish (
Scyliorhinus canicula) in the Western English Channel beam trawl fishery.
Fisheries Research, 71: 121-124.
Rotllant, J., Ruane, N. M., Dinis, M. T., Canario, A. V., and Power, D. M. 2006. Intra-
adrenal interactions in fish: catecholamine stimulated cortisol release in sea bass
(
Dicentrarchus labrax L.). Comp Biochem Physiol A Mol Integr Physiol, 143: 375-381.
Wedemeyer, G. A., Barton, B. A., and McLeay, D. J. 1990. Stress and acclimation.
In
Methods of Fish Biology, pp. 451-489. Ed. by C. B. Schreck, and P. B. Moyle. American
Fisheries Society, Bethesda MD.
Wendelaar Bonga, S. E. 1997. The stress response in fish. Physiological Reviews, 77: 591-
625.
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