Introduction

About 1,000 Cirripèdae species have been described. The pedunculate barnacle Pollicipes elegans belongs to the class Crustacea, subclass Cirripedia, order Thoracica, suborder Lepadomorpha (Pilsbry, 1909). The Swedish botanist Charles Linnaeus in 1750 named the genus Lepas ("Shellfish") and local species such as L. anatifera "bracket duck" and L. anserifera and "bracket hen", respectively), and these pedunculate geese continue to be called barnacles (Villena, 1995).

There are two related species Pollicipes polymerus and Pollicipes elegans which Laguna (1985)states that their distribution ranges from Baja California (Mexico) to Peru. Barnacles are used as food in some countries, such as Portugal and Spain, and are served in gourmet restaurants, sometimes running out locally. In Ecuador this crustacean is served in restaurants that have recognized the flavor of the species and local cevicheras, due to its preparation and seafood flavor, which is often imported as a dietary substitute, prices range between 2 to 3 dollars per kilogram.

Some genera of this group have been found to be symbionts, thus described as beneficial to many, while others turn out to be parasites. (Marine Research Institute, 2013).. There are about a dozen species of barnacles that are present on ships and submerged parts in different marine installations, such as jetty piles, oil platforms, floats, buoys and mooring cables. This species can also increase the corrosion of metals, including stainless steel. In general, barnacles are hermaphroditic (i.e., each individual has both male and female reproductive systems) in species where populations are sparsely found. In most shallow-water species their fertilization is internal (Newman, 1987).

In medicine, the secretory gland by which barnacles adhere is studied because of its unusual properties and its possible use as a dental cement. These populations are grouped in formations called "patches" whose size varies according to locality (Kamella & Zeballos, 1988). Its wall has a calcareous shell, composed of a series of articulated plates attached to the substrate, with an opening at the top called the operculum, and has cirri, which are articulated legs that can extend into the water to capture small plants and animals from the environment (plankton) (Newman, 1987).

In Peru, the species Pollicipes elegans has been studied for some years, (Kamella & Zeballos, 1988) started a population monitoring in the southern sea of Yasilia, Paita; Chilca, Lima; with a total of 15 patches of 1m², with a total of 56,160 organisms. In Lobos Afuera Island since 1995 an information bank has been developed, where the population of the species began with a total of 39,495,834 organisms (Samamé & Quevedo). By 2001 (Carbajal, Ramirez, Cruz, & Javier Castro, 2001)observed that the population numbered about 22,508,688 organisms with respect to previous evaluations. In May 2002, this number decreased to 2,517,496 organisms (Cruz, Castro, Carbajal, & Javier Castro, 2001). (Cruz, Castro, Carbajal, & Ramiréz, 2002).. This island currently has a Regulation Measure established since the last evaluations carried out in 2001, where it was proposed to recover the resource due to its great importance. In September 2010 the amount found was 416,440 organisms, an amount that alarmed the evaluators because the natural banks of P. elegans were being annihilated by local collectors(Ramiréz & Cruz, 2010). The background information summarized during the evaluations on Lobos Afuera Island in Peru is presented as an example, so that the current information from the chosen sampling point can be considered as a reference, due to the anthropological intervention in the place. Inadequate extraction of the species causes alterations in the food chain. In addition, we quantified the impact that the artisanal fishery of the place causes to the rocky area of Puerto Engabao, Canton Playas, Guayas Province, hoping that this work contributes as an axis for possible studies where the dependence of human beings is balanced with their eagerness to subsist at the expense of such fragile organisms of the marine ecosystem.

Materials and methods

Study area

In Ecuador there is a tourist spot that is well known for its large waves that strongly attack the rocky area it shelters. Puerto Engabao is one of the municipalities that make up the Playas canton, belonging to the province of Guayas (Illustration 1). The species commonly extracted are: sea cucumbers, oysters, shells, goat legs or barnacles. The population evaluation was carried out in three seasons, taking advantage of the low tide.

Illustration 1
Study area (Source: Google earth 2015).

Quadrant methodQuadrant method

The area is comprised of 150 m of rocky area, where the stations called A, B, and C are located parallel to the sea and spaced 50 m apart. From the lowest tide line towards high tide, each quadrant is spaced 6 m wide, counting the number of organisms in 1m² (Illustration 2).

Illustration 2.
Systematic sampling stratification using the quadrant method (Source: Google Earth 2015).

Method for quantification of organisms

For sample collection, the methodology proposed by Samamé & Quevedo (1995-1997) was applied. (1995-1997)in which Pollicipes elegans colonies are observed to establish an area where the organisms are well grouped. Using a box of 0.25 m² (truly populated area), the number of organisms was counted with a total of 218, which will be used to apply the following formula.

P= AC/m²

Where P= population, A= area truly populated with barnacles and C/m²= number or weight per square meter, an indicator of density. The population was calculated as the product of the density per area and the estimated area with barnacles in one square meter. Subsequently, 90 specimens were taken from the environment, taking into account several morphological aspects of the species, such as: length of capitulum, length of peduncle, size and wet weight. Pearson's correlation (length-weight) was applied to these data, which were recorded and tabulated for statistical interpretation in the Excel computer program.

Extraction of organisms

The catch of barnacles in the study area was monitored, estimating the average number of organisms extracted per day. In the first sampling, around 298 organisms were counted, 536 in the second and around 348 in the third. These counts were carried out when the people involved in the collection allowed it because they were following up on an artisanal activity that could affect their economy (Illustration 3).

Illustration 3
Pollicipes elegans in situ and specimen collection

Physicochemical parameters

To record the different physical and chemical parameters, we obtained the collaboration of the Shrimp Larvae Laboratory AMBARTEK S.A., which provided us with equipment such as: mercury thermometer to measure temperature, OPTIKA hand refractometer (HR-150-double scale) to quantify salinity, OHAUS analytical balance to determine the wet weight and a YSI-model 55 oxygen meter to obtain readings of dissolved oxygen in situ.

Results

Quadrant method

In the first sampling in May, the largest population was recorded with a total of 10246 organisms at point A (low sea), while in October the smallest population was recorded with a total of 327 barnacles at point B (low sea). In most of the sampling stations the high tide registered 0 organisms/m² Figure 1.

Figure 1.
Population of Pollicipes elegans sp. in the rocky zone by month.

Rostral carina length

The specimens were percentage by class intervals with ranges from 9 to 13mm occupying 4.4% of the population as well as from 19 to 23mm, while from 14 to 18mm the percentage was 0%, from 24 to 28mm 8.9%, and from 33 to 37mm 10%, 71% of the population goes from 29 to 32mm rostral carina length so they would be adults and from 38 to 42mm 1.1% was recorded which would be the mature organisms in the study area. The margin of error is 0 to 1 for the samples (Figure 2).

Figure 2
Percentage frequency of barnacle rostral carina length.

Population and biomass.

With a total of 3488 organisms/m², the population per patch observed in the rocky zone of Puerto Engabao was estimated to obtain the density per area. The biomass in the pink zone was 86.97 kg and the total population reached 10464 organisms in three patches of 1m². According to the empirical table proposed by Samamé & Quevedo (1995-1997)the maximum size recorded is 40 mm, with a minimum value of 11 mm and a sample average of 29 mm in length, although more than 22.2 % of the population is around 30 mm (Table 1).

Table 1

Barnacle population and biomass.

Weight-size

PEARSON correlation

Of the 90 specimens taken from the environment, the maximum size was 110mm and minimum 21mm with an average of 75mm. The maximum weight recorded was 13.1g and minimum 0.7g with an average of 8.3g. The Pearson correlation had an r² of 0.7788, where weight and length had a relationship of 88.25% (Figure 3).

Figure 3.
Pearson correlation (weight-height).

The artisanal fishery that has been carried out at low tide reported a maximum of 618 organisms in September and its minimum value was 109 in June with an average harvest of 272 barnacles per day. During mid-tide, the maximum value was 121 in August and the minimum value was 10 with an average of 44 organisms. At high tide the collection of these organisms was 0 due to low population (Figure 4).

Figure 4.
Organisms collected in months of fishing.

Parameters

From May to October the average temperature in the rocky area of Puerto Engabao was 33°C, with a salinity of 31.5 ppm and dissolved oxygen averaging 5.34 mg/L (Figure 5).

Figure 5.
Physical and chemical parameters of the area.

At present, there is no research work available in Ecuador on barnacle species, which is why we worked with the methodology applied in Peru, due to the influence of the warm El Niño current that at the time contributed to the displacement of the species according to (Paredes, Cardoso, & Tarazona, 2004).. With records that defend the hypothesis that this phenomenon recorded in 1998, migrated more than 15 different crustaceans from its coasts, among them Pollicipes elegans (Carbajal, Ramirez, & Castro, 1998).. This species has now been located in several sites in Ecuador such as: Punta Carnero, Santa Elena and the Galapagos Islands. (Julian Peréz Correa, 2015).

The abundance of the species occurs at the lowest tides where the breaker is very beneficial, so much so that the density exceeds 3488 organisms per m², with an average weight of 0.7 to 13.1 grams/organism in the rocky area of Puerto Engabao. Other authors such as (Francisco Pinilla García, 1996) who in his evaluation in the area of Lobitos - Peru, obtained 30,592 barnacles/m², with an average weight of 0.43 to 1.85 g/ barnacle, with which both the density and weight per m² differ from the sampling location due to the amount of nutrients in the area that would consider the samples very flaccid.

From May to October 2015, the physical-chemical parameters had an average surface temperature of 33°C, with a dissolved oxygen of 5.34 mg/L, these parameters being ideal for barnacle development in the area. While in an evaluation by (Cruz, Castro, Carbajal, & Ramiréz, 2002) its average surface temperature was 20.0 °C and with an average dissolved oxygen of 2.93 ml/l in the Peruvian sea. Reason for which I differ with the data because the sampling method was developed in large cliffs and stepping stones vertically, while the coasts of Ecuador are very rich in crevices where the sampling and the definition of the tidal strata were developed horizontally.

Conclusions

Puerto Engabao harbors a total of 3488 organisms per square meter at low tide where the population distribution is homogeneous.

From May to October, station A recorded the highest number of organisms in the area with 10246, which gradually decreased to 2289 as the season progressed, while point B recorded a maximum of 654 barnacles and 327 at the end of the season. Point C recorded 3706 and 654 organisms in the last month of sampling.

Stations A, B and C presented variations at the population level. At low tide, a maximum of 10246 and a minimum of 327 organisms were obtained, while at mid-tide, a maximum of 2616 and a minimum of 0 were counted.

With a Pearson correlation of 88.25%, organisms with a total length of 110 mm and a maximum weight of 13.1 grams were found, while the average size is 75 mm with a weight of 8.3 grams. Therefore, from a weight of 8.5 grams and a length of 90 millimeters, the barnacle resource found in the rocky area of Puerto Engabao would not be affected and its repopulation would be more abundant in the area, without affecting the economy of the families that benefit from this resource.

In the Port of Engabao, Pollicipes elegans is not currently considered, nor has it been established with the relevant authorities, size and size of collection to ensure the sustainability of the species in its habitat. Therefore, training the community involved on barnacles would be a topic that would bring great changes, given the lack of management of the resource.

It is known that in the buoys that limit the artisanal fishing zones on certain beaches, the development of these organisms is even higher than the averages exposed in this work. Therefore, knowing their diet and parameters would be one more issue that generates uncertainty to the Pollicipes elegans topic.

This information reflects the need to obtain data on sexual maturity and fertilization percentage, which will help us to ensure that the collection is not only due to size and weight, but also to provide security to the larvae in the environment, which in its development process adheres to an adult barnacle and then adheres to the substrate.

References

Carbajal, W., Ramirez, P., & Castro, J. (1998). The influence of the 1997-1998 El Niño on some invertebrates in northern Peru. Peru: Instituto del Mar del Peru.

Carbajal, W., Ramirez, P., Cruz, J. d., & Javier Castro (2001). Evaluation of the population of the Barnacle Barnacle Barnacle Pollicipes Elegans in the Lobos Afuera Islands. Lambayaque: IMAPRE.

Cruz, J. d., Castro, J., Carbajal, W., & Ramiréz, P. (2002). Evaluation of Pollicipes Elegans in the Lobos de Afuera Islands. Lambayeque-Peru: IMAPRE.

Francisco Pinilla García. (1996). Temporal variation of the density and biomass of the barnacle Pollicipes elegans population in the Lobitos area, Piura, Peru. Lima: Thesis.

Marine Research Institute (2013, February 17). Nazca Institute. Retrieved from Instituto Nazca: http://institutonazca.org

Julian Peréz Correa (2015). Community Ecological Records. Santa Elena: Ecoregistros.

Kamella, A., & Zeballos, J. (1988). Distribution and density of barnacles Pollicipes elegans (Crustacea: Cirripedia) in the Peruvian mediolitoral (Yasila, Paita; Chilca, Lima). Lima: Boletín Instituto del Mar.

Newman, W. (1987). Evolution of cirripedes and their major groups, in: Southward. Barnacle biology, 3-42.

Paredes, C., Cardoso, F., & Tarazona, J. (2004). Temporal distribution of tropical mollusks and crustaceans in the Peruvian Province and their relationship with El Niño events. Peru: Faculty of Biological Sciences UNMSM.

Pilsbry (1909). Report on barnacles of Peru. Peru: Natural Museum Proceeding.

Ramiréz, P., & Cruz, J. d. (2010). OUTSIDE WOLF ISLANDS: EVALUATION OF OCTOPUS Octopus mimus Gould, 1852 AND PERCEBES Pollicipes elegans (Lesson, 1831), . LAMBAYEQUE: IMAPRE.

Samamé, M., & Quevedo, M. (1995-1997). Population and biomass of barnacles Pollicipes elegans Lesson, 1830 in Lobos de Tierra and Lobos de Afuera islands. Lambayeque-Peru: IMAPRE.

Villena, G. (1995). Reproductive aspects of barnacles Pollicipes elegans from the Yacila area, Paita, Peru. Peru: Pesquería UNALM.