WO2011107633A1

WO2011107633A1 - Oceanographic device for collecting plankton samples, suitable for oceanographic rosettes

Info

Publication number: WO2011107633A1
Application number: PCT/ES2011/000052
Authority: WO
Inventors: Juan Ignacio Gonzalez Gordillo
Original assignee: Universidad De Cádiz (Otri)
Priority date: 2010-03-05
Filing date: 2011-02-24
Publication date: 2011-09-09
Also published as: ES2377070A1; ES2377070B2

Abstract

The invention relates to an oceanographic device for collecting plankton samples, suitable for oceanographic rosettes. The device includes a casing, a plankton net and a collector. The casing protects the net and includes an upper opening and a lower opening. The upper opening has a cover that can be opened or closed by a spring mechanism controlled by a tension cable. The casing also comprises windows at the upper end thereof and a lower fixed cover including holes for discharging water. The plankton net is secured both to the upper edge of the casing and to the lower fixed cover. The collector, which is used to collect the filtered plankton, is secured to the external surface of the lower fixed cover and comprises side windows for discharging the filtered water. If preserved samples are to be obtained, the aforementioned windows are located in the upper half of the collector.

Description

OCEANOGRAPHIC EQUIPMENT FOR THE COLLECTION OF SAMPLES OF PLANCTON APPLICABLE TO OCEANOGRAPHIC ROSETS.

SECTOR OF THE TECHNIQUE.

Technology and oceanographic instrumentation

STATE OF THE TECHNIQUE PRIOR TO THE DATE OF PRESENTATION.

There are currently three ways to obtain plankton samples of a given depth range: plankton networks with controlled opening and closing systems, oceanographic bottles and suction systems combined with plankton networks. Each of these techniques is chosen based on the size of the organisms that wish to be studied, their abundance and their density in the environment. The use of plankton networks is aimed at sampling organisms belonging to larger fractions (greater than 200 microns), for which it is necessary to filter large volumes of water to obtain representative samples. For the collection of samples at certain depths, the simplest networks include opening and closing systems operated by messengers (a small weight that is sent from the surface and slides along the traction cable to the network). However, with this type of system it is difficult to know precisely the depth at which the network closes, since the cable that the trailer frequently describes a curved line during traction, complicating the calculations to estimate the real depth of the equipment.

Other plankton networks, such as the MultiPlankton Sampier or the Longhurst-Hardy Plankton Recorder, use automated systems for opening and closing the networks, including depth sensors, which ensures the collection of plankton samples at a specific depth. But this type of equipment implies a robust, bulky and heavy design of the equipment, which make its management depends on the use of a boat equipped with pens or porches ad hoc and personnel specialized in deck maneuvers.

On the other hand, sampling of organisms belonging to fractions smaller than 200 microns with plankton nets is rare, since the high sizes of the entrance openings of the networks and / or the drag speeds developed by the vessels used cause a rapid clogging of the networks giving rise to useless samples. Whatever the case may be, the sampling methodology itself implies that the network should be taken to the depth of sampling and subsequently uploaded on board. When the depth of study is high, exceeding 1000 m, the start and turn times of plankton networks can cover several hours, when the truly effective sampling time implies few minutes.

Consequently, existing plankton networks are currently not viable for the collection of planktonic organisms belonging to small fractions (less than 200 microns) at high depths, since their management entails a high cost in terms of material, human infrastructure and time of execution.

A current alternative to the use of plankton networks could be the use of oceanographic bottles (such as Pat. N2 5,094,113 - USA). The use of these bottles, when embedded in oceanographic rosettes, reduces maneuver times and the additional personnel involved to zero, since samples directed to planktonic studies are collected at the same time as other tasks are performed as profiles for measurements of physical variables -chemistry and collection of water samples for measurement of other biological variables. However, carrying out this type of sampling, the volume of filtered water could be insufficient, mainly for the oceanographic bottles generally used have a capacity of 12 I). This problem is accentuated when sampling in oligotrophic areas where a larger volume of sampling is required. Thus, the samples obtained by these methods may not be representative due to the low volume filtered.

Finally, there are mechanisms that combine a water suction system and plankton networks that filter that volume of water driven (see Pat. N ⁹ 3.466.782 - USA). This ingenuity ensures the filtering of a sufficient volume of water so that the sample is representative of the planktonic community under study and, in addition, when working stationary, the depth of sampling can be specified. A mechanical opening and closing system operated by messengers prevents contamination of the samples by organisms of other depths. On the contrary, the equipment needs a complicated system of gears to force the entry of water to the network, the measurement of the filtered flow is not very satisfactory.

Patent N3 US 2005/0274204 Al (USA) represents a considerable improvement in the technique of collecting plankton samples with respect to those described above, being able to obtain samples at certain depths, simply and at a low cost. However, the protection received by the filter mesh is scarce, protection that becomes indispensable when the mesh used is equal to or less than 20 microns (micrometer used for example to obtain microplankton samples), which makes it excessively delicate for handling aboard oceanographic ships in which blows or small hooks are inevitable. In parallel, its use coupled to oceanographic rosettes requires the reservation of two of the automatic triggers located in the rosettes, preventing them from being used for other purposes. As for the configuration of the terminal manifolds from which the sample is extracted, the morphology is very similar in all existing ones. According to the type of fastening with the plankton net, there are basically two types: i) threaded, easy to release and ii) fixed by means of a clamp, which is more difficult to clean (see patents ⁵ 4,399,629 - USA). However, for any of these configurations these manifolds are blind (as in Pat US 4558534 or Pat US 2005/0274204 Al) or provided with a tap-like key. In the case of blind collectors, sample extraction involves disassembling the collector and dumping its contents into the storage bottle (Pat ⁹ US 3900982), and a funnel must be used frequently. The correct cleaning of this type of collectors is not fast, since part of the small organisms remain attached to the walls of the collector when it is turned to the funnel and some expertise is needed to avoid losing organisms. The collectors provided with a final key avoid having to turn the collector for cleaning, which considerably facilitates its use, but the key mechanism itself makes the effective diameter for the output of the filtered material to be very small, causing frequent jams in this point. Therefore, collectors must be designed with a lower outlet but avoiding keys or any type of mechanism that involves a trap for the sampled organisms.

Explanation of the invention.

The purpose of this invention is to obtain samples of planktonic organisms at any depth, simultaneously with water sampling performed with oceanographic rosettes, without the use of complicated mechanical devices and with low manufacturing and handling costs. Its design also allows the fixation of the organisms sampled instantly, avoiding predation between them. The oceanographic equipment for the collection of plankton samples is implemented to work coupled to a rosette of oceanographic bottles, but could also be used autonomously if it is attached to a weighted oceanographic cable.

The general operation of the oceanographic equipment for the collection of plankton samples is based on the channeling and filtering of a certain volume of water through a small plankton network contained within a rigid structure (housing), provided in turn with a terminal collector . During use, the water to be sampled enters through an upper opening, crosses the plankton network of a specific micrometer and exits through windows and evacuation holes. The organisms are retained by the network and accumulate in the terminal collector from which they are subsequently extracted. As it is a procedure without automatisms, a constant water flow must be established to ensure the entry of organisms into the network. This flow is achieved thanks to the vertical displacement of the equipment (from bottom to top) along the water column. In the case of being used mounted on an oceanographic rosette, it is the one that, when traveling a vertical path during its use, ensures the entry of water into the apparatus, between depth limits established by the researcher.

It is known that the general procedure for using an oceanographic rosette consists of two phases. During the first, the equipment is constantly lowered to a previously defined maximum depth. During the second phase, the oceanographic rosette is also steadily risen but stopping at certain depths where it takes the necessary water samples. It is during this ascending route, from the maximum depth reached to a given higher one, where the oceanographic equipment for collecting samples of plankton performs the filtration of water and the sampling of organisms, optimizing as already mentioned, the maneuver of use of the oceanographic rosette. Upon reaching the upper level of sampling chosen, the entry of water into the network is interrupted by closing the upper opening by an airtight lid. This closure is achieved by releasing a tensioning cable that joins the upper cover of the oceanographic equipment and one of the automatic triggers of the remote closing mechanism used by the oceanographic rosette to close the different sampling bottles. At this time, springs placed on the top cover of the system act by closing the housing. Thus, the entrance of water to the equipment is sealed, preventing the entry of water from other depths and, therefore, preventing contamination of the sample by other organisms. Finally, the system has a collector located at the lower end where the collected organisms will accumulate. Depending on the purpose of the samples, it may be preferred that the organisms arrive preserved or alive to the surface. Due to this, the configuration of the collector can be of two types: i) a collector provided with small side windows for the evacuation of the filtered water and which can be filled with a certain amount of fixing solution; and i) a collector with large side windows that allows high evacuation efficiency and where living organisms are retained. In the case of the collector provided with a space full of preservative solution, the organisms when they reach this point come into contact with this solution and die almost instantaneously, avoiding predation between them. This aspect is very relevant when the samples are taken at great depths and take a few hours to surface. On the other hand, the collector is easy to place and remove, allowing rapid replacement and convenient sample washing. The design of the collector allows the sample to be extracted vertically through a flexible plastic tube of small length located at its lower end. This tube is closed by an easy-to-remove plastic cap. This mechanism prevents organisms from being retained in any type of mechanism and their removal is quick and safe.

The calculation of the volume of filtered water is estimated by solving the following equation:

h being the depth sampling start (maximum depth), h _f the final depth (closed network) r the radius of the inlet opening. The equipment is designed to be placed in the metal structure (frame) of an oceanographic rosette, adapting to it and without impeding the placement of the remaining sampling bottles. In fact, to fit each case, the equipment could be manufactured of the same diameter and length as the oceanographic bottles that make up the rosette, thus avoiding incompatibilities. Although the carcass and the net have pre-established measures depending on the type of rosette used, the mesh may have a variable micrometer, appropriate to the type of organisms to be sampled. DESCRIPTION OF THE FIGURES.

Figure 1. General view of the Oceanographic Equipment for the collection of plankton samples applicable to oceanographic rosettes.

Figure 2. Longitudinal section of the Oceanographic Equipment for the collection of plankton samples applicable to oceanographic rosettes, where the plankton network housed inside it can be seen. Figure 3. Detail of the fastening of the plankton net to the lower cover of the housing.

Figure 4. Detail of the top cover that tightly closes the housing.

Figure 5. Detail of the fastening of the collector to the lower cover of the housing.

Figure 6. General view of the collector designed for filling with fixing solution. Figure 7. Overview of the standard manifold

MODE OF EMBODIMENT OF THE INVENTION.

The oceanographic equipment for the collection of plankton samples applicable to oceanographic rosettes comprises in a single dedicated structure:

- A housing that allows the anchoring of the sample collection equipment in other oceanographic equipment, channels and regulates the flow of water to be filtered and gives protection to the plankton network.

- A plankton network, of variable micrometer according to the fraction interested in being sampled.

- A collector where the directly preserved plankton sample is accumulated, and which allows its rapid extraction and washing.

The size and shape of the housing is optimized to be assembled to an oceanographic rosette, without making it difficult to place other bottles and the anchoring mechanism to place it in oceanographic rosettes is adapted to the shape and size of the housing.

The housing has an opening in its upper and lower part, which allows, when the first one is open, that water flows through it, dragging the planktonic organisms to the plankton network housed inside.

The upper opening of the housing has a lid whose closure is controlled by a spring mechanism. This lid remains open during sampling, thanks to a thin tensioning cable that is fixed at the opposite end to one of the triggers of the oceanographic rosette. The closing of the cover is produced by releasing the tensioning cable and the action of springs located in the housing that work in opposition to the tensioning cable. Once the upper lid is closed, water is prevented from entering while the equipment rises thanks to the arrangement of O-rings that make the seal tight. The housing has at its lower end a fixed cover that has water drainage holes and in which the lower end of the plankton net (on the inside) and the collector (on the outside) is secured.

Both the upper and lower cover of the housing are easily removable to change the type of network that houses inside, because it can be replaced by another depending on the fraction of plankton that you want to collect. Once fixed, the plankton net remains immobile, attached to the upper edge and lower cover of the housing. Attached to the outer face of the lower cover of the housing, there is a collector, whose function is to collect the filtered plankton. The shape and size of this collector will vary depending on the fraction of sampled plankton and the housing used. The collector will be attached to the housing by means of an anchoring mechanism that allows its rapid removal or replacement.

The collector has side windows for the evacuation of filtered water, each of them provided with a filter mesh of the same micrometer as the net mounted inside the housing, which prevents the exit of the captured organisms and at its lower end, the collector presents a hole with a flexible plastic tube for sample extraction. The size of the side evacuation windows of the collector can vary according to whether or not to obtain a preserved sample. In the case that it is preferred to obtain a conserved sample, the windows will be small in size, with a length less than 50% of the total length of the collector, they will be located in the upper half, leaving the bottom part of the collector as a receptacle for liquids, the which can be filled with a fixing solution, which fixes the organisms collected, preventing predation from occurring between them.

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WAY THAT THE INVENTION IS SUSCEPTIBLE OF INDUSTRIAL APPLICATION

It is not considered necessary to make this description more extensive so that any person skilled in the art understands the scope of the invention and the advantages derived therefrom.

The materials, shape, size and arrangement of the elements will be subject to variation, provided that this does not imply an alteration to the essentiality of the invention.

The terms in which this report has been described must always be taken broadly and not limitatively.

Claims

1. Oceanographic equipment for the collection of samples of plankton applicable to oceanographic rosettes, comprising in a single dedicated structure: - A housing that allows the anchoring of the sample collection equipment in other oceanographic equipment, channels and regulates the flow of water to filter and protect the plankton network.

2. Oceanographic equipment for the collection of samples of plankton applicable to oceanographic rosettes, according to claim 1, characterized in that the size and shape of the housing is optimized to be assembled to an oceanographic rosette, without hindering the placement of other bottles.

3. Oceanographic equipment for the collection of samples of plankton applicable to oceanographic rosettes, according to claims 1 and 2, characterized in that the housing has an anchoring mechanism, adapted to the shape and size of the housing, to be placed in oceanographic rosettes.

4. Oceanographic equipment for the collection of samples of plankton applicable to oceanographic rosettes, according to claims 1 to 3, characterized in that the housing has an opening in its upper and lower part, which allows, when the first is open, that water flows through it, dragging the planktonic organisms to the plankton network housed inside.

Oceanographic equipment for the collection of samples of plankton applicable to oceanographic rosettes, according to claims 1 to 4, characterized in that the upper opening of the housing has a lid whose opening or closing is controlled by a spring mechanism.

Oceanographic equipment for the collection of samples of plankton applicable to oceanographic rosettes, according to claims 1 to 5, characterized in that the lid remains open during sampling, thanks to a thin tensioning cable that is fixed at the opposite end to one of the triggers of the oceanographic rosette.

Oceanographic equipment for the collection of samples of plankton applicable to oceanographic rosettes, according to claims 1 to 6, characterized in that the closure of the lid is produced by releasing the tensioning cable and the action of springs located in the housing that work in opposition to the Tensioning cable.

Oceanographic equipment for the collection of samples of plankton applicable to oceanographic rosettes, according to claims 1 to 7, characterized in that the upper lid once closed prevents the entry of water while the equipment rises thanks to the provision in it of O-rings that make the hermetic set.

9. Oceanographic equipment for the collection of samples of plankton applicable to oceanographic rosettes, according to claims 1 to 8, characterized in that the housing has windows in the upper end that allow the rapid evacuation of water during the descent of the equipment.

10. Oceanographic equipment for the collection of samples of plankton applicable to oceanographic rosettes, according to claims 1 to 9, characterized in that the housing has at its lower end a fixed cover in which the lower end of the plankton net is secured (by the internal part) and the collector (for the external part).

11. Oceanographic equipment for the collection of samples of plankton applicable to oceanographic rosettes, according to claims 1 to 10, characterized in that the lower cover of the housing has water drainage holes.

12. Oceanographic equipment for the collection of samples of plankton applicable to oceanographic rosettes, according to claims 1 to 11, characterized in that both the upper and lower cover of the housing are easily removable to change the type of network that houses inside.

13. Oceanographic equipment for the collection of samples of plankton applicable to oceanographic rosettes, according to claim 1, characterized in that a plankton network of size and shape determined by the housing is housed inside.

14. Oceanographic equipment for the collection of samples of plankton applicable to oceanographic rosettes, according to claims 1 and 13, characterized in that the micrometer (mesh light) of the plankton network is not fixed, but is determined by the fraction of plankton that You want to collect.

15. Oceanographic equipment for the collection of samples of plankton applicable to oceanographic rosettes, according to claims 1 to 14, characterized in that the plankton net remains immobile by being fixed to the upper edge and lower cover of the housing.

16. Oceanographic equipment for the collection of samples of plankton applicable to oceanographic rosettes, according to claim 1, characterized in that it has a collector of variable shape and size according to the fraction of sampled plankton and the housing used, with the function of collecting the filtered plankton.

17. Oceanographic equipment for the collection of samples of plankton applicable to oceanographic rosettes, according to claims 1 and 16, characterized in that the collector is fixed to the outer face of the lower cover of the housing by means of an anchoring mechanism that allows its rapid removal or substitution.

18. Oceanographic equipment for the collection of samples of plankton applicable to oceanographic rosettes, according to claims 1, 16 and 17, characterized in that the collector has at its lower end a hole with a flexible plastic tube for the extraction of the sample, hermetically sealed by an easily removed cap.

19. Oceanographic equipment for the collection of samples of plankton applicable to oceanographic rosettes, according to claims 1 and 16 to 18, characterized in that the collector has side windows for the evacuation of filtered water, each provided with a filter mesh of the same micron that the network mounted inside the housing, which prevents the exit of the captured organisms.

20. Oceanographic equipment for the collection of samples of plankton applicable to oceanographic rosettes, according to claims 1 and 16 to 19, characterized in that the size of the side evacuation windows of the collector can vary in size according to whether or not to obtain a preserved sample.

21. Oceanographic equipment for the collection of samples of plankton applicable to oceanographic rosettes, according to claims 1 and 16 to 20, characterized in that in the case that it is preferred to obtain a conserved sample the windows will be of small size, with a length less than 50% of the total length of the collector and located in the upper half, leaving the lower part of the collector as a receptacle for liquids.

22. Oceanographic equipment for the collection of plankton samples applicable to oceanographic rosettes, according to claims 1 and 16 to 21, characterized in that the design of the collector used to obtain preserved samples is capable of being filled with a fixing solution.

23. Oceanographic equipment for the collection of samples of plankton applicable to oceanographic rosettes, according to claims 1 and 16 to 22, characterized in that in the case that it is not necessary to obtain a conserved sample, the evacuation windows may have a length greater than that mentioned in claim 21, ensuring better evacuation of filtered water.