Harper v Minister for Sea Fisheries

The licensing system which the Fisheries Act 1959 Tas. and the Sea Fisheries Regulations 1962 (Tas.) establish in relation to abalone fisheries in Tasmanian waters is not a mere device for tax collecting. Its basis lies in environmental and conservational considerations which require that exploitation, particularly commercial exploitation, of limited public natural resources be carefully monitored and legislatively curtailed if their existence is to be preserved. Under that licensing system, the general public is deprived of the right of unfettered exploitation of the Tasmanian abalone fisheries. What was formerly in the public domain is converted into the exclusive but controlled preserve of those who hold licences. The right of commercial exploitation of a public resource for personal profit has become a privilege confined to those who hold commercial licences. This privilege can be compared to a profit à prendre. In truth, however, it is an entitlement of a new kind created as part of a system for preserving a limited public natural resource in a society which is coming to recognize that, in so far as such resources are concerned, to fail to protect may destroy and to preserve the right of everyone to take what he or she will may eventually deprive that right of all content.

In that context, the commercial licence fee is properly to be seen as the price exacted by the public, through its laws, for the appropriation of a limited public natural resource to the commercial exploitation of those who, by their own choice, acquire or retain commercial licences. So seen, the fee is the quid pro quo for the property which may lawfully be taken pursuant to the statutory right or privilege which a commercial licence confers upon its holder. It is not a tax. That being so, it is not a duty of excise.

The plaintiff is a Tasmanian fisherman who has been diving for and taking abalone from the coastal waters of Tasmania since 1977. The defendant Minister administers Pt II of the Fisheries Act 1959 Tas. ("the Act") under which the Sea Fisheries Regulations 1962 ("the Regulations") were made. The defendant Director is responsible for the issue on behalf of the Minister of licences to take abalone in State fishing waters pursuant to the Regulations. Abalone is a mollusc which the Australian Encyclopaedia, 5th ed. (1988), describes thus:

The animal lives in a simple curved spiral shell with a row of holes around the edge that allows water to pass over the gills. The body is little more than a large muscular foot with a pair of eyes on stalks at one end and sensory tentacles around the margin. Abalone inhabit the waters adjacent to Tasmania. In the mature state, abalone remain in contact with the seabed, normally attached by suction to rock surfaces. They are able to move in snail-like fashion by means of their single muscular foot. In the larval stage, abalone drift supporting themselves in the water column for some days before settling on the seabed. When young, abalone have a high mortality rate.

The commercial exploitation of abalone in Tasmania commenced in 1963. They are taken by divers diving to the seabed and individually prising the abalone free from rocks by means of a knife or other similar instrument. Abalone meat and abalone shell are marketable commodities. Abalone constitute a finite but renewable resource, the quantity of which is dependent on certain biological factors (namely growth rate, reproductive potential and natural mortality rates) and the rate of exploitation. The absence of management arrangements to limit the rate of exploitation to a level which enables the stock of abalone to replace itself may lead to the depletion of stock to such an extent that commercial exploitation may become uneconomic.

Since 1985, a limitation has been imposed on the quantity of abalone which might be harvested commercially from "State fishing waters" as defined by s. 3A of the Act. This has been done by means of a licensing system under the Regulations. Commercial abalone licences were allocated in each year to 125 persons to take a quota of 28 "units", the quantity to be taken per unit being adjusted from year to year. The amount of the allowable take per unit has been progressively reduced as follows: 1985 1.1 tonnes 1986 1.0 tonne 1987 0.95 tonne 1988 0.855 tonne 1989 0.60 tonne

The plaintiff applied for and was granted commercial abalone licences in respect of each of the years 1987, 1988 and 1989. The amount which he was required to pay and did pay to obtain each licence was calculated in accordance with reg. 17A of the Regulations as in force in the respective years. The material regulations were made by the Governor pursuant to s. 9(1)(h) of the Act. At all material times during 1987 and prior to its amendment on 9 December 1987, reg. 17A of the Regulations, so far as material, provided as follows: -

(1) Subject to regulation 17AA, no person shall take any abalone in State fishing waters unless he is the holder of -

(a) a subsisting commercial abalone licence sold and issued for that purpose under this regulation; or

(1a) The price at which a commercial abalone licence may be sold is a price calculated at $360 for each tonne of abalone that the holder of the licence is authorized to take while the licence is in force.

In accordance with this regulation, the plaintiff was required to pay and paid $9,576 to obtain the 1987 licence.

At all material times from 9 December 1987 until its amendment on 13 December 1988, reg. 17A so far as material, provided as follows: -

(1) Subject to regulation 17AA, no person shall take any abalone in State fishing waters unless he is the holder of: -

(a) a subsisting commercial abalone licence issued for that purpose under this regulation; or

(1a) The prescribed fee for the issue of a commercial abalone licence is the amount for each tonne of abalone that the holder of the licence is authorized to take pursuant to the licence, being an amount calculated in accordance with the formula - P = V x 0.05 C where -

"V" represents the gross value, in accordance with a declaration by the Director published in the Gazette, of the total quantity of abalone taken in State fishing waters by the holders of commercial abalone licences during the 12 month period ended on 30th June in the year preceding the licensing year in relation to each of those licences; and

"C" represents the total quantity in tonnes of abalone that the holders of all commercial abalone licences may take pursuant to those licences during the licensing year in relation to each of those licences, being a total quantity in accordance with a determination by the Minister published in the Gazette.

(1b) For the purposes of the formula specified in subsection (1A) -

(a) "licensing year", in relation to a commercial abalone licence, means the period of 12 months ending on the date on which the licence ceases to be in force pursuant to subregulation (3)(b); and

(b) a reference to any other year is a reference to a period beginning on 1st January and ending on the following 31st December.

(1c) The prescribed fee for the issue of a commercial abalone licence is payable in full at the time when the application for the licence is made to the Director or is payable by instalments as follows: -

(a) an instalment of half of that fee payable at the time when the application is so made;

(b) an instalment of the remaining half of that fee payable before 1st May following the payment of the instalment referred to in paragraph (a).

(3aaa) If the holder of a commercial abalone licence has not paid the full amount of the prescribed fee for the issue of the licence before 1st May in the year at the end of which the licence would, apart from this subregulation, cease to be in force, that licence ceases to be in force on 1st May in that year.

In accordance with this regulation, the plaintiff was required to pay and paid $18,079 to obtain the 1988 licence.

At all material times since 13 December 1988, reg. 17A, so far as material, has provided as follows: -

(1) Subject to regulation 17AA, no person shall take any abalone in State fishing waters unless he is the holder of -

(a) a subsisting commercial abalone licence issued and sold for that purpose under this regulation; or

(1a) The Minister may issue and sell commercial abalone licences.

(1b) The price at which a commercial abalone licence may be sold pursuant to subregulation (1A) is as follows: -

(a) where the quantity of abalone authorized to be taken pursuant to the licence does not exceed 15 tonnes - $28,200;

(b) where the quantity of abalone authorized to be taken pursuant to the licence exceeds 15 tonnes - $40,000;

(c) where the licence sold is one that has been surrendered by the previous holder of the licence - the balance of the sale price for the licence unpaid by that holder, plus $50.

(2) An application for a commercial abalone licence: -

(c) shall, subject to subregulation (3A), be accompanied by -

(iii) the prescribed fee for the issue of the licence.

To obtain the 1989 licence, the plaintiff was required to enter into a contract with the Minister for and on behalf of the Crown in right of Tasmania for the purchase of the licence. The basic price of the licence was adjusted to an amount of $17,976 plus a fee of $100 for issuing the licence. On or about 9 January 1989 the plaintiff paid to the Minister the sum of $8,988, being 50 per cent of the sum of $17,976.

The plaintiff brought this action against the State of Tasmania and the other two defendants to challenge the validity of the requirement to pay the amounts which he paid to obtain the 1987, 1988 and 1989 licences. Dawson J. stated a case raising the question:

Is Regulation 17A of the Sea Fisheries Regulations 1962 Tas as amended from time to time or any part thereof invalid in its application for the years -

in respect of commercial abalone licences held by the plaintiff?

The plaintiff asserts and the defendants deny that reg. 17A in its varying forms purports to impose a duty of excise contrary to s. 90 of the Constitution. The resolution of this contest calls for an examination of the operation of the statutory licensing regime.

Apart from statute, the right of the public to fish in Tasmanian tidal waters is as stated by Viscount Haldane L.C. speaking for the Privy Council in Attorney-General (British Columbia) v. Attorney-General (Canada) [1] :

Since the decision of the House of Lords in Malcolmson [Malcomson] v. O'Dea [2] , it has been unquestioned law that since Magna Charta no new exclusive fishery could be created by Royal grant in tidal waters, and that no public right of fishing in such waters, then existing, can be taken away without competent legislation. This is now part of the law of England, and their Lordships entertain no doubt that it is part of the law of British Columbia. And [3] : In the tidal waters, whether on the foreshore or in creeks, estuaries, and tidal rivers, the public have the right to fish, and by reason of the provisions of Magna Charta no restriction can be put upon that right of the public by an exercise of the prerogative in the form of a grant or otherwise. It was assumed throughout the hearing, no doubt correctly, that the waters in which the Tasmanian abalone fishery was situated were tidal waters. Accordingly, the right of the owner of the soil over which the waters flow (whether the owner be the Crown or not) to enjoy the exclusive right of fishing in those waters or to grant such a right to another as a profit à prendre is qualified by the paramount right to fish vested in the public: seeAttorney-General (British Columbia) v. Attorney-General (Canada) [4] . In Malcomson v. O'Dea [5] , it was held that, after Magna Charta, the Crown, in whom the title to the bed of tidal navigable rivers was vested, was precluded from granting a private right of fishery, the right of fishery being in the public. The law so stated was followed in Neill v. Duke of Devonshire [6] . And in Lord Fitzhardinge v. Purcell [7] , although Parker J. held that the Crown might grant title to the bed of the sea or of a tidal navigable river to a subject, his Lordship held that no such grant can operate to the detriment of the public right of fishing [8] . The existence of a public right to fish in tidal waters was accepted by Stephen and Jacobs JJ. in New South Wales v. The Commonwealth [Seas and Submerged Lands Case] [9] . But the right of fishing in the sea and in tidal navigable rivers, being a public not a proprietary right, is freely amenable to abrogation or regulation by a competent legislature: see Attorney-General (British Columbia) v. Attorney-General (Canada) [10] ; Attorney-General (Canada) v. Attorney-General (Quebec) [11] . Although there is authority for the view that the public right of fishing is sustained by the Crown's title to the sub-soil (Mayor, &c. of Carlisle v. Graham [12] ) the competence of a State legislature to make laws regulating a right of fishing in such waters is not dependent upon the State's possession of a proprietary right in the bed of the seas or rivers over which such waters flow. Lord Herschell pointed out that "there is a broad distinction between proprietary rights and legislative jurisdiction": Attorney-General (Canada) v. Attorney-Generals (Ontario, Quebec, and Nova Scotia) [13] . 1. [1914] A.C. 153, at p. 170. 2. (1863) 10 H.L. Cas. 593 [11 E.R. 1155]. 3. [1914] A.C., at p. 171. 4. [1914] A.C., at pp. 167-168. 5. (1863) 10 H.L. Cas., at p. 618 [11 E.R., at pp. 1165-1166]. 6. (1882) 8 App. Cas. 135, at pp. 138-139, 178, 179. 7. [1908] 2 Ch. 139. 8. [1908] 2 Ch., at pp. 166-167. 9. (1975) 135 C.L.R. 337, at pp. 419, 421, 423, 489. 10. [1914] A.C., at pp. 170, 172. 11. [1921] 1 A.C. 413, at pp. 421-422, 427. 12. (1869) L.R. 4 Exch. 361, at pp. 367-368. 13. [1898] A.C. 700, at p. 709.

The public right of fishing in tidal waters is not limited by the need to preserve the capacity of a fishery to sustain itself. The management of a fishery to prevent its depletion by the public must be provided for, if at all, by statute. In Goodman v. Mayor of Saltash [14] , there was a dispute between the respondent corporation as the owner (by ancient grant) of a several oyster fishery in the river Tamar and certain inhabitants of ancient tenements who claimed a right to dredge for oysters at a certain period of the year. In reference to an objection that the dredging tended to the destruction of the fishery, Lord Selborne L.C. said [15] :

The tendency to the "destruction" of the oyster fishery can mean no more than what must always be in the power of the public, where there is a general public right of fishing namely, the exhaustion of the fishery, by taking excessive numbers of fish. Fish (whether floating or shell-fish) are not part of the soil or freehold. Their capture is merely the ordinary mode of the perception of those fruits and profits which a fishery produces. They grow, and are reproduced continually from spat and spawn; and if it is true that a fishery might possibly be exhausted by excessive fishing, it is only in the same way that a field may be exhausted by over-cropping. 1. (1882) 7 App. Cas. 633. 2. (1882) 7 App. Cas., at p. 646.

The Regulations prescribe a management regime for the abalone fishery in State fishing waters. "State fishing waters" are defined by s. 3A of the Act:

A reference in this Act to State fishing waters is -

(a) a reference to all waters that are within the limits of the State, other than inland waters;

(c) for purposes in relation to a fishery that is to be managed in accordance with the law of the State pursuant to an arrangement under Division 3 of Part IIA - a reference to any waters to which the legislative powers of the State extend with respect to that fishery, whether by virtue of section 5 of the Coastal Waters (State Powers) Act 1980 of the Commonwealth or otherwise; and

The Tasmanian abalone fishery falls within s. 3A(c). An arrangement was entered into on 6 March 1987 by the Commonwealth and Tasmania under s. 12H(4) of the Fisheries Act 1952 Cth ("the Commonwealth Act") and under s. 24H of the Act for the management in accordance with the laws of Tasmania of the abalone fishery in the area of waters adjacent to the State described in the arrangement. Those waters include the coastal waters of the State (as defined in s. 4A of the Commonwealth Act) and waters within the Australian fishing zone (as defined in s. 4(1) of the Commonwealth Act): s. 12A(2) of the Commonwealth Act. For reasons stated by the Court in Port MacDonnell Professional Fishermen's Association Inc. v. South Australia [16] the legislative powers of Tasmania extend to the enactment of laws for the management of the abalone fishery in the waters described in that arrangement. The validity and effect of the Regulations do not depend upon the title of the Crown in right of Tasmania to the bed of the adjacent sea.

In addition to the prohibition against the taking of abalone contained in reg. 17A of the Regulations, reg. 17B provides, inter alia:

(1) Subject to regulation 17AA and this regulation, no person shall in State fishing waters take by diving or swimming under water -

(ii) a subsisting non-commercial diving licence issued for that purpose under this regulation.

Regulation 44(1)(o) prohibits any person from taking in State fishing waters more than ten abalone in any one day unless he is the holder of a subsisting commercial abalone licence; and reg. 44(1)(ra) prohibits the holder of a commercial abalone licence to take in State fishing waters more than the quantity of abalone specified as the quantity that may be taken by the holder of the licence. That quantity is specified in the licence in accordance with reg. 19ab. Regulation 44(3) makes any failure to comply with the Regulations an offence. The public right of fishing for abalone in State fishing waters is thus abrogated and private statutory rights to take abalone in limited quantities are conferred on the holders of commercial and non-commercial abalone licences. The Regulations thus control the exploitation of a finite resource in order to preserve its existence. They seek to achieve this end by imposing a general prohibition on exploitation followed by the grant of licences for the taking of limited quantities of abalone. The only compensation, if compensation it be, derived by the public for loss of the right of fishing for abalone consists in the amounts required to be paid by holders to obtain abalone licences under the Regulations.

The plaintiff contends that the amount required by reg. 17A in its differing forms to be paid to obtain a commercial abalone licence is a tax and a duty of excise. The fact that the amount payable pursuant to reg. 17A is in the form of a licence fee does not preclude the classification of that amount as a tax: see, for example, M. G. Kailis (1962) Pty. Ltd. v. Western Australia [17] ; Gosford Meats Pty. Ltd. v. New South Wales [18] . Indeed, in Attorney-General (Canada) v. Attorney-Generals (Ontario, Quebec, and Nova Scotia) [19] the Privy Council held that the taxing power of the Canadian Parliament extended to the imposition of "a tax by way of licence as a condition of the right to fish". The plaintiff points to the relationship between the amount required to be paid to obtain a licence on the one hand and the quantity of abalone which might lawfully be taken on the other and finds an analogy with the fee exacted for a licence to process fish in M. G. Kailis which this Court held to be a duty of excise. Although fish processing, not the taking of fish, was the subject of the licence in M. G. Kailis, the plaintiff submits that the taking of abalone is the first step in the production of abalone meat and abalone shell - the marketable commodities - and that an amount which is required to be paid to take abalone is a tax upon that step in production.

1. (1974) 130 C.L.R. 245. 2. (1985) 155 C.L.R. 368. 3. [1898] A.C., at p. 713.

The defendants deny that the amounts required to be paid to obtain a licence are duties of excise. Several arguments are raised in support of that submission. The principal argument starts with the proposition that abalone have such a degree of attachment to and dependence on the seabed that they should be regarded as part of it in the same way that mussels were said to be part of the bed of the river Clyde in Parker v. Lord Advocate [20] . (Though it may be doubted whether the ratio of that decision was that the mussels in the mussel scalps were part of the soil: [21] .) Then it was said that the Coastal Waters (State Title) Act 1980 Cth had vested in Tasmania the same right and title to the property in the seabed beneath the coastal waters of that State as would belong to Tasmania if that seabed were beneath waters of the sea within the limits of Tasmania: see s. 4(1) of that Act. Arguing that under that Act Tasmania became the owner of the abalone attached to the seabed beneath coastal waters and that Tasmania already was the owner of the abalone attached to the seabed beneath waters within the limits of the State, the defendants submit that the amount required to be paid to obtain a licence to take the abalone is a royalty. A royalty, in the sense of a payment made to the owner of land for the right to take away things which are part of or naturally attached to the soil (Stanton v. Federal Commissioner of Taxation [22] ), is not a tax and, not being a tax, cannot be a duty of excise. Alternatively, the amount required to be paid to obtain a licence is said to be paid for a profit à prendre - for the right to take abalone rather than for the abalone taken: see Halsbury's Laws of England, 4th ed., vol. 18, p. 254, par. 601. It is immaterial to this argument whether the abalone are part of the seabed or are merely found on the seabed: Beckett (Alfred F.) Ltd. v. Lyons [23] . The payments required to be made under reg. 17A, so the argument runs, are in the nature of a royalty and are neither a tax nor a duty of excise. The plaintiff meets these arguments by challenging the proposition that abalone or the right to take abalone belonged to the owner of the seabed and by challenging both the validity of the Coastal Waters (State Title) Act and its efficacy to vest in Tasmania ownership of the seabed beneath the coastal waters of the State. To the extent that the defendants' case depends upon Tasmania's ownership of the seabed beneath the coastal waters and the waters within the limits of the State, it is but a partial answer to the plaintiff's argument. The State fishing waters include waters in the Australian fishing zone adjacent to the coastal waters of Tasmania and no suggestion was made that Tasmania has any proprietary rights in the seabed beneath the waters in the Australian fishing zone.

1. [1904] A.C. 364. 2. [1904] A.C., at p. 377. 3. [1956] St.R. Qd 421, at p. 431; (1955) 92 C.L.R. 630, at p. 641. 4. [1967] Ch. 449, at pp. 480-481.

Finally, the defendants embrace an argument which depends not on proprietary rights in the seabed but upon the exercise of legislative power over the abalone fishery in State fishing waters. In my opinion, that argument should be upheld. Accordingly, it becomes unnecessary to consider Tasmania's proprietary rights in the seabed and the arguments that the amounts paid by the plaintiff to obtain a licence are royalties charged by the Crown in right of Tasmania as the owner of the seabed or are payments for a profit à prendre in or over the seabed so owned.

The foundation of this argument is that none of the amounts paid to obtain a commercial abalone licence in the years 1987, 1988 and 1989 is a tax and that a fee which is payable to a State or to a State authority which is not a tax cannot be a duty of excise. Duties of excise constitute a category of taxes for the purposes of the Constitution (see s. 55) and the power to impose duties of excise, which s. 90 makes exclusive to the Parliament of the Commonwealth, is part of the power to impose taxation: Vacuum Oil Co. Pty. Ltd. v. Queensland [24] . What, then, is the character of the amounts paid to obtain the licences?

As we have seen, the Act and the Regulations abrogate the public right to fish for abalone in the State fishing waters and confer private statutory rights on the several licence holders, commercial and non-commercial, to take limited quantities of abalone. Although any member of the public may apply for and be granted a non-commercial licence, not every member of the public is a licence holder, and those who may lawfully take abalone do so not in exercise of a public right to fish but in exercise of the statutory right of a licensee. As licensees under the Act are the only persons who enjoy the right to take abalone from the Tasmanian fishery, the public being excluded, the right they enjoy is similar to the common of piscary - a right of fishing in another's waters to the exclusion of the public. Such a common law right is a profit à prendre (see Halsbury's Laws of England, 4th ed., vol. 6, p. 215, pars 581, 582) but at common law it is not available in tidal waters. When a natural resource is limited so that it is liable to damage, exhaustion or destruction by uncontrolled exploitation by the public, a statute which prohibits the public from exercising a common law right to exploit the resource and confers statutory rights on licensees to exploit the resource to a limited extent confers on those licensees a privilege analogous to a profit à prendre in or over the property of another. A limited natural resource which is otherwise available for exploitation by the public can be said truly to be public property whether or not the Crown has the radical or freehold title to the resource. A fee paid to obtain such a privilege is analogous to the price of a profit à prendre; it is a charge for the acquisition of a right akin to property. Such a fee may be distinguished from a fee exacted for a licence merely to do some act which is otherwise prohibited (for example, a fee for a licence to sell liquor) where there is no resource to which a right of access is obtained by payment of the fee.

If the right to fish for abalone were created in diminution of proprietary rights of the owner of the seabed and without the owner's consent, some question as to the validity of the law might have arisen, for the legislature of a State may not be competent to create proprietary rights out of property beyond the boundaries of the State and to which the State has no title: cf. Attorney-General (Canada) v. Attorney-Generals (Ontario, Quebec, and Nova Scotia) [25] . That problem does not arise in this case, however, for the management of the fishery in accordance with Tasmanian law is arranged between the Commonwealth and Tasmania. If title be needed to support the fishing rights conferred on the abalone licence holders, the arrangement made under the Act and the Commonwealth Act testifies to the consent of the Crown in right of the Commonwealth and of Tasmania to the creation of those rights.

The next question is whether the amount required to be paid by a licensee to obtain the right to fish is a tax. In Air Caledonie International v. The Commonwealth [26] , the Court cited the features which Latham C.J. adopted in Matthews v. Chicory Marketing Board (Vict.) [27] , as a general statement of positive and negative attributes which, if they all be present, suffice to stamp an exaction of money with the character of a tax:

a compulsory exaction of money by a public authority for public purposes, enforceable by law, and not a payment for services rendered. The Court [28] commented on this general statement: The third [comment] is that the negative attribute - "not a payment for services rendered" - should be seen as intended to be but an example of various special types of exaction which may not be taxes even though the positive attributes mentioned by Latham C.J. are all present. Thus, a charge for the acquisition or use of property, a fee for a privilege and a fine or penalty imposed for criminal conduct or breach of statutory obligation are other examples of special types of exactions of money which are unlikely to be properly characterized as a tax notwithstanding that they exhibit those positive attributes. 1. (1988) 165 C.L.R. 462, at pp. 466-467. 2. (1938) 60 C.L.R. 263, at p. 276. 3. (1988) 165 C.L.R., at p. 467.

As the amounts payable to obtain an abalone fishing licence are of the same character as a charge for the acquisition of property, they do not bear the character of taxes. They are not duties of excise.

Accordingly, the answer to the question in the case stated is: No.

We agree with Brennan J. and would add only the following comment.

Whilst the proper conclusion is that the amount paid for a commercial abalone licence is not a tax and, therefore, is not a duty of excise, that conclusion flows from all the circumstances of the case. Most important is the fact that it is possible to discern a relationship between the amount paid and the value of the privilege conferred by the licence, namely, the right to acquire abalone for commercial purposes in specified quantities. In discerning that relationship it is significant that abalone constitute a finite but renewable resource which cannot be subjected to unrestricted commercial exploitation without endangering its continued existence.

However, the conclusion reached by Brennan J. by no means carries with it the consequence that no exaction of money can constitute a tax if it is demanded for the purpose of conserving a public natural resource. If such an exaction otherwise exhibits the characteristics of a tax it will properly be seen as such. In particular, if the exaction "has no discernible relationship with the value of what is acquired, the circumstances may be such that the exaction is, at least to the extent that it exceeds that value, properly to be seen as a tax": Air Caledonie International v. The Commonwealth [28] . This may be so notwithstanding that the exaction is one means of ensuring the conservation of a natural resource; there are, of course, other ways in which such a resource may be protected. Clearly the line between a price paid for the right to appropriate a public natural resource and a tax upon the activity of appropriating it may often be difficult to draw. But what is otherwise a tax is not converted into something else merely because it serves the purpose of conserving a natural public resource.