Choosing the right fish at the seafood counter can be overwhelming. Whether you’re comparing swordfish vs marlin for your next grilling session, evaluating swordfish vs tuna for nutrition, or wondering if swordfish vs salmon is healthier, understanding the key differences helps you make informed decisions. From taste profiles and cooking methods to mercury levels and omega-3 content, each fish offers unique advantages. This comprehensive guide compares swordfish against marlin, tuna, salmon, mako shark, sailfish, and halibut—covering everything from marlin vs swordfish taste distinctions to pregnancy safety, sustainability, and price—so you can choose the perfect fish for your needs.

Quick Comparison: Swordfish vs Other Fish

Swordfish vs Marlin: Marlin has leaner, pink flesh with a milder flavor; swordfish is meatier, fattier, and has a richer taste. Swordfish has higher mercury (0.995 ppm) than most marlin species.

Swordfish vs Tuna: Tuna is leaner with more protein; swordfish is fattier with more omega-3s and vitamin D. Swordfish has nearly 3x more mercury (0.995 ppm vs 0.386 ppm).

Swordfish vs Salmon: Salmon has more omega-3s (1,921mg vs 764mg) and dramatically less mercury (0.022 ppm vs 0.995 ppm—45x less). Salmon is the healthier choice for regular consumption.

Are you standing at the seafood counter wondering which fish to choose? Whether you’re comparing swordfish vs marlin taste, evaluating swordfish vs tuna nutrition, or considering swordfish vs salmon for health benefits, this comprehensive guide provides evidence-based comparisons to help you make informed decisions.

Understanding the differences between swordfish and other popular fish species—including marlin, tuna, salmon, mako shark, sailfish, and halibut—empowers you to choose the best option for your culinary preferences, nutritional needs, and health considerations. From marlin vs swordfish taste distinctions to mercury level comparisons, we’ll explore every aspect you need to know.

Swordfish vs Marlin: Key Differences Explained

Physical Differences: Swordfish vs Marlin

Swordfish (Xiphias gladius):

• Belong to Xiphiidae family (only species in family)
• Flat, broad, sword-like bill resembling an actual sword
• Tall, crescent-shaped dorsal fin
• Rounded, robust body built for deep-water endurance
• Silver-gray coloring throughout
• Lack scales as adults
• Large, round eyes adapted for deep, dark waters
• Can reach 14 feet and 1,400+ pounds

Marlin (Istiophoridae family):

• Include blue marlin, black marlin, striped marlin, white marlin
• Round, pointed, spear-like bill
• Lower dorsal fin extending further back, resembling a sail
• More elongated, streamlined body
• Brilliant blue top with silver-gray underside
• Vertical stripes that shimmer blue or purple
• Can reach up to 16 feet and 1,800+ pounds (black marlin)

The bill shape is the most obvious distinction: swordfish bills are flat and blade-like, while marlin bills are round and spear-like.

Habitat and Behavior

Swordfish:

• Hunt in deeper waters, often diving 200-2,000 feet
• Solitary predators
• Hunt primarily at night (nighttime feeders)
• More migratory, traveling vast distances with seasonal changes
• Use bills to slash at schooling baitfish, stunning prey
• Can dive to extreme depths; lack swim bladders for buoyancy control
• Prefer cooler, deeper water layers

Marlin:

• Hunt in relatively shallow waters near seamounts, continental shelf drop-offs
• Surface hunters in warm tropical waters
• Diurnal feeders (hunt during daytime)
• Less migratory than swordfish
• Known for spectacular acrobatic displays—leaping and breaching
• Can reach speeds over 50 mph (black marlin up to 80 mph)
• Prefer warm surface waters

Marlin vs Swordfish Taste Comparison

Swordfish Taste:

• Mild, slightly sweet flavor
• Meaty, steak-like texture often compared to beef
• White to pinkish flesh when raw; beige when cooked
• Firm, dense, moist texture that holds up to high-heat cooking
• Fattier fish with higher oil content
• Rich, robust flavor more pronounced than marlin
• Not overly “fishy” tasting despite being oily fish

Marlin Taste:

• Subtly mild flavor with slight sweetness
• Firm, pink to red flesh (color varies by species)
• Dense, flaky texture similar to tuna
• Leaner meat with lower fat content than swordfish
• Less intense flavor—milder than swordfish
• Blue marlin has richer, fuller flavor closest to swordfish
• Slight smoky undertone when prepared properly

Consensus: Most seafood enthusiasts prefer swordfish for its heartier, more flavorful meat. Marlin is excellent for those seeking a lighter, more delicate fish experience. The pink flesh of marlin tastes somewhat like swordfish but considerably lighter overall.

Swordfish vs Marlin Nutrition

Per 3-ounce (85g) cooked serving:

Nutrient	Swordfish	Marlin
Calories	146-172	120-134
Protein	20-23g	20-22g
Total Fat	6-7g	3-4g
Omega-3	764mg	500-600mg
Mercury	0.995 ppm	0.485 ppm (avg)
Vitamin D	95% DV	35% DV
Selenium	142% DV	110% DV

Key Nutritional Differences:

• Marlin is leaner with less fat and fewer calories
• Swordfish provides more omega-3 fatty acids
• Swordfish has significantly more vitamin D
• Marlin generally has lower mercury levels (though still moderate-high)
• Both are excellent protein sources with complete amino acids
• Marlin has slightly higher protein per calorie

Cooking Methods: Swordfish vs Marlin

Best for Swordfish:

• Grilling: Firm texture holds up beautifully; 4-5 minutes per side
• Pan-searing: Creates excellent crust; finish in oven for thick steaks
• Broiling: Quick, high-heat method preserving moisture
• Baking: Gentle cooking with marinades at 400-425°F
• Kebabs: Dense flesh stays on skewers without falling apart

Best for Marlin:

• Sashimi-style: Best served raw in thin slices (preferred method)
• Sushi: Excellent in rolls with rice
• Rare seared: Quickly sear all sides, serve rare like tuna steak
• Ceviche: Peruvian-style with lime juice
• Grilling: Works well but avoid overcooking (becomes dry)

Important note: Never overcook marlin—it should be rare to medium-rare. Swordfish can handle being cooked through without drying out.

Sustainability and Availability

Swordfish:

• North Atlantic populations have recovered significantly
• Well-managed in U.S. waters; sustainable when sourced properly
• Available year-round
• Moderately priced ($18-30/pound depending on quality)
• FDA recommends maximum 1 serving weekly for adults
• Pregnant women should avoid completely

Marlin:

• Some populations face overfishing pressure
• Blue marlin populations are vulnerable
• Catch-and-release encouraged for sport fishing
• Less commonly sold commercially (more of a game fish)
• More expensive ($25-40+/pound when available)
• Can be consumed more frequently than swordfish (lower mercury)
• Still not recommended during pregnancy

Swordfish vs Tuna: Health and Taste

Species Distinctions

Tuna (Genus Thunnus):

• Seven species: bluefin, yellowfin, albacore, bigeye, southern bluefin, blackfin, longtail
• Part of mackerel family
• Fast-swimming, schooling fish
• Found in all major oceans
• Vary dramatically in size (20-1,500 pounds)

Swordfish:

• Single species: Xiphias gladius
• Solitary predator
• Deeper-dwelling than most tuna
• More limited commercial varieties

Swordfish vs Tuna Taste

Swordfish:

• Mild, slightly sweet, nutty flavor
• White-fleshed with hint of pink
• Dense, meaty texture like beef steak
• Firm, moist consistency
• Not overly fishy
• Holds up well to bold seasonings

Tuna:

• Rich, somewhat meaty taste (varies by species)
• Deep red flesh (raw) turning tan/gray when cooked
• Oily, buttery, flaky texture
• Bluefin: Most flavorful, fattiest, prized for sashimi
• Yellowfin: Medium flavor, firm texture
• Albacore: Mildest, lightest meat
• Skipjack (canned light): Strongest flavor, softest texture

Taste winner: Personal preference determines this. Swordfish offers consistently mild, accessible flavor perfect for those who dislike “fishy” taste. Tuna provides range from mild (albacore) to intensely flavorful (bluefin).

Nutritional Comparison: Swordfish vs Tuna

Per 3-ounce (85g) cooked serving:

Nutrient	Swordfish	Yellowfin Tuna	Albacore Tuna
Calories	146	130	109
Protein	20-23g	25g	25g
Total Fat	6-7g	3g	2.5g
Omega-3	764mg	237mg	733mg
Vitamin D	95% DV	6% DV	40% DV
Vitamin B12	67% DV	98% DV	115% DV
Selenium	119% DV	98% DV	98% DV
Mercury	0.995 ppm	0.354 ppm	0.358 ppm

Key Differences:

• Tuna has more protein: 25g vs 20-23g per serving
• Swordfish is higher in fat: Particularly healthy unsaturated fats
• Swordfish dominates vitamin D: 95% vs 6-40% DV
• Tuna wins on B12: Nearly 50% more than swordfish
• Mercury is critical: Swordfish has nearly 3x more mercury than tuna
• Omega-3 varies: Swordfish and albacore similar; yellowfin much lower

Health Verdict: Swordfish vs Tuna

Tuna is healthier for regular consumption due to significantly lower mercury levels. While both provide excellent nutrition, tuna’s 2.5-3x lower mercury content (0.354-0.386 ppm vs 0.995 ppm) makes it safer to eat more frequently.

Recommendations:

• Swordfish: Maximum 1 serving weekly for adults; avoid during pregnancy
• Yellowfin/Skipjack tuna: 2-3 servings weekly safe for most adults; pregnant women can have 1 serving weekly
• Albacore tuna: Maximum 1 serving weekly due to moderate mercury; pregnant women limit to 6 oz weekly

Cooking Applications

Swordfish excels in:

• Grilling (holds shape perfectly)
• Kebabs (doesn’t fall apart)
• Thick steaks (maintains moisture)
• Heavy marinades (absorbs flavors well)

Tuna excels in:

• Sushi and sashimi (especially bluefin)
• Searing rare (traditional preparation)
• Canned applications (skipjack, albacore)
• Poke bowls (raw preparations)
• Salads and sandwiches (canned)

Swordfish vs Salmon: The Health Champion

Fundamental Differences

Salmon (Salmonidae family):

• Anadromous fish (born in freshwater, mature in ocean, return to freshwater to spawn)
• Multiple species: Atlantic, king/chinook, sockeye, coho, pink, chum
• Naturally pink/orange/red flesh from astaxanthin (carotenoid from diet)
• Cold-water fish
• Both wild-caught and farmed widely available

Swordfish:

• Exclusively saltwater, warm-ocean predator
• Single species
• White to pale pink flesh
• Deep-water dweller
• Only wild-caught (not farmed)

Swordfish vs Salmon Nutrition

Per 3-ounce (85g) cooked serving:

Nutrient	Swordfish	Wild Salmon	Farmed Salmon
Calories	146	177	206
Protein	20-23g	19g	19g
Total Fat	6-7g	10g	13g
Omega-3	764mg	1,921mg	2,260mg
Vitamin D	95% DV	97% DV	127% DV
Vitamin B12	67% DV	127% DV	117% DV
Selenium	119% DV	75% DV	66% DV
Mercury	0.995 ppm	0.022 ppm	0.022 ppm

Critical Distinction: Mercury

Salmon contains 45 times less mercury than swordfish (0.022 ppm vs 0.995 ppm). This dramatic difference makes salmon infinitely safer for:

• Pregnant women (2-3 servings weekly recommended)
• Nursing mothers (unlimited safe servings)
• Young children (2-3 servings weekly)
• Regular weekly consumption by all adults

Omega-3 Champion: Salmon Wins

Wild salmon provides 2.5x more omega-3s than swordfish (1,921mg vs 764mg), with farmed salmon delivering nearly 3x more (2,260mg vs 764mg). For cardiovascular health, brain function, and anti-inflammatory benefits, salmon is objectively superior.

Taste and Texture Comparison

Swordfish:

• Mild, slightly sweet, nutty
• Dense, meaty, steak-like
• Firm texture that doesn’t flake easily
• White flesh
• Not “fishy” tasting
• Appeals to those who don’t like traditional fish flavor

Salmon:

• Rich, buttery, distinctive flavor
• Tender, flaky texture
• Pink to deep red flesh
• Noticeably “fish” flavor (though not unpleasant)
• Wild salmon: Firmer, leaner, more pronounced flavor
• Farmed salmon: Fattier, buttery, milder

Taste preference: Highly individual. Swordfish suits those seeking mild, meat-like fish. Salmon appeals to those who enjoy richer, more distinctive seafood flavor.

Health Verdict: Salmon Dominates

Salmon is dramatically healthier than swordfish for regular consumption:

✅ 45x less mercury (critical for safety) ✅ 2.5-3x more omega-3 fatty acids (better heart/brain health) ✅ Safe during pregnancy (essential advantage) ✅ Can be eaten 2-3x weekly (vs once weekly for swordfish) ✅ More vitamin B12 ✅ Comparable vitamin D

Only swordfish advantage: Higher selenium content (though both provide ample amounts)

Cooking Versatility

Swordfish best methods:

• Grilling (legendary for this)
• Broiling
• Pan-searing
• Kebabs
• Can withstand high heat without drying

Salmon best methods:

• Baking (most popular)
• Pan-searing (skin-side first)
• Grilling (use cedar planks to prevent sticking)
• Poaching (gentle, moist method)
• Smoking (traditional preparation)
• Raw (sushi-grade in poke, sashimi)

Swordfish vs Mako Shark

Physical and Species Differences

Mako Shark:

• Shortfin mako (Isurus oxyrinchus) most commonly consumed
• True shark (Chondrichthyes—cartilaginous skeleton)
• Fastest shark species (up to 45 mph)
• Warm-blooded (unusual for sharks)
• Blue-gray top, white underside
• Can reach 12 feet and 1,200+ pounds

Key Distinctions:

• Mako is a shark (cartilage, not bone); swordfish is bony fish
• Mako has shark-like pointed snout; swordfish has flat bill
• Mako has multiple rows of teeth; swordfish has no teeth as adults

Taste Comparison

Mako Shark:

• Mild, slightly sweet flavor very similar to swordfish
• Dense, firm, meaty texture (often compared to swordfish)
• White to pinkish flesh
• Lacks any “fishy” or “shark-like” ammonia taste (if fresh)
• Often described as “chicken of the sea” alternative to tuna

Swordfish:

• Nearly identical mild, sweet taste profile
• Comparable meaty texture
• Similar density and cooking properties

Verdict: Taste is virtually indistinguishable for most people. Both offer mild, accessible flavor perfect for non-fish-lovers.

Nutritional Comparison

Per 3-ounce (85g) cooked serving:

Nutrient	Swordfish	Mako Shark
Calories	146	134
Protein	20-23g	21g
Total Fat	6-7g	4.5g
Omega-3	764mg	550mg
Mercury	0.995 ppm	0.730 ppm

Nutritional Differences:

• Mako is slightly leaner (fewer calories/fat)
• Swordfish has more omega-3 fatty acids
• Both have HIGH mercury levels (among highest of all fish)
• Mako has moderately less mercury (still dangerous levels)

Mercury Warning: Both Are High-Risk

Both swordfish and mako shark are on the FDA’s “DO NOT EAT” list for:

• Pregnant women
• Nursing mothers
• Women planning pregnancy
• Children under 6 years

Adults should limit consumption to once monthly maximum for either species due to mercury accumulation risk.

Sustainability Concerns

Mako Shark:

• Listed as “Endangered” (IUCN Red List)
• Populations declining globally
• Overfished in many regions
• Bycatch in longline fisheries
• Recommendation: Avoid eating mako shark entirely for conservation reasons

Swordfish:

• North Atlantic populations recovered and well-managed
• Sustainable options available when sourced responsibly
• Better conservation status than mako

Ethical verdict: Choose swordfish over mako shark. Mako populations need protection from fishing pressure.

Swordfish vs Sailfish

Physical Identification

Sailfish (Istiophorus species):

• Part of billfish family with marlin
• Distinctive enormous dorsal fin (sail) – can be raised or lowered
• Brilliant blue coloring with vertical stripes
• Long, slender bill
• Most visually spectacular billfish
• Smaller than swordfish: 6-10 feet, 120-220 pounds
• Fastest fish on Earth – up to 68 mph in short bursts

Key Differences:

• Sailfish sail (dorsal fin) is dramatically larger than swordfish fin
• Sailfish are much smaller overall
• Sailfish have rounder, more slender bills
• Swordfish are significantly heavier and more robust

Culinary Use and Taste

Sailfish:

• Rarely consumed commercially – primarily catch-and-release game fish
• Most anglers release sailfish due to conservation efforts
• When eaten, has firm, white flesh
• Mild flavor similar to other billfish
• Leaner than swordfish with less fat

Swordfish:

• Widely commercially available
• Standard restaurant offering
• Preferred eating fish compared to sailfish
• Meatier, more flavorful than sailfish
• Better culinary reputation

Verdict: Swordfish is far superior for eating. Sailfish are best appreciated as magnificent game fish and released.

Conservation Status

Sailfish:

• Populations relatively healthy compared to some billfish
• Catch-and-release strongly encouraged
• Not typically sold commercially in U.S.
• Important ecotourism draw for sport fishing

Swordfish:

• Commercially harvested
• Sustainable in many regions
• Available for consumption with proper sourcing

Ethical recommendation: Admire sailfish, release them. Eat sustainably-sourced swordfish instead.

Swordfish vs Halibut

Species Fundamentals

Halibut (Hippoglossus species):

• Flatfish (both eyes on one side of head)
• Lives on ocean floor
• Atlantic and Pacific species
• Can reach 8 feet and 500+ pounds (Pacific halibut)
• White, flaky flesh
• Cold-water fish

Fundamental Difference: Halibut is a flatfish with completely different body structure and ecology than swordfish.

Taste Comparison

Halibut:

• Very mild, slightly sweet flavor
• Delicate, flaky texture
• Pure white flesh
• Lean, low-fat fish
• Subtle, clean taste
• Less assertive than swordfish

Swordfish:

• Mild but more pronounced flavor
• Meaty, steak-like texture
• Firmer, denser flesh
• Higher fat content
• More robust eating experience

Taste verdict: Halibut is milder and more delicate. Swordfish is meatier and more substantial. Choose halibut for subtle flavor; swordfish for heartier meal.

Nutritional Comparison

Per 3-ounce (85g) cooked serving:

Nutrient	Swordfish	Halibut
Calories	146	94
Protein	20-23g	19g
Total Fat	6-7g	2g
Omega-3	764mg	465mg
Mercury	0.995 ppm	0.241 ppm
Vitamin D	95% DV	32% DV

Key Nutritional Differences:

• Halibut is significantly leaner (fewer calories/fat)
• Halibut has 4x less mercury than swordfish (0.241 vs 0.995 ppm)
• Swordfish provides more omega-3s (764mg vs 465mg)
• Swordfish dominates vitamin D (95% vs 32% DV)
• Both are excellent protein sources

Health Verdict: Halibut is Safer

Halibut is the healthier choice primarily due to 4x lower mercury levels. While swordfish offers more omega-3s and vitamin D, halibut’s mercury advantage makes it safer for:

• More frequent consumption (2-3 servings weekly vs once weekly)
• Pregnant women (can have 1 serving weekly vs complete avoidance)
• Children (can eat occasionally vs avoidance)

Cooking Applications

Halibut best for:

• Baking
• Poaching
• Gentle pan-frying
• Fish tacos (tender, flaky texture)
• Delicate preparations where fish flavor shouldn’t dominate

Swordfish best for:

• Grilling (won’t fall apart)
• High-heat cooking
• Kebabs
• Bold marinades and seasonings
• Hearty main courses

Price Comparison

Halibut: Typically more expensive ($30-45/pound) due to:

• Limited wild stocks
• Highly prized texture
• Strict fishing quotas

Swordfish: Moderately priced ($18-30/pound):

• More abundant commercially
• Year-round availability

Mercury Levels: Complete Comparison Chart

Understanding mercury content is crucial for safe consumption:

Fish	Mercury (ppm)	FDA Category	Max Frequency
Swordfish	0.995	Avoid	1x/week adults only
Mako Shark	0.730	Avoid	1x/month adults only
Tuna (yellowfin)	0.354	Good Choice	2-3x/week
Tuna (albacore)	0.358	Good Choice	1x/week
Marlin	0.485	Good Choice	1-2x/week
Halibut	0.241	Good Choice	2-3x/week
Salmon	0.022	Best Choice	Unlimited
Sardines	0.013	Best Choice	Unlimited

FDA Pregnancy Guidelines:

• Avoid: Swordfish, shark (including mako)
• Limit: Albacore tuna (6 oz weekly maximum)
• Safe: Salmon, sardines, skipjack tuna, halibut (8-12 oz weekly)

Cooking Temperature and Methods Guide

Safe Internal Temperature for All Fish: 145°F (63°C)

Grilling Time Guide

Fish	Thickness	Time per Side	Notes
Swordfish	1 inch	4-5 minutes	Holds shape excellently
Marlin	1 inch	3-4 minutes	Avoid overcooking (serve rare)
Tuna	1 inch	2-3 minutes	Best rare to medium-rare
Salmon	1 inch	4-6 minutes	Watch for white albumin
Halibut	1 inch	3-4 minutes	Delicate – use grilling basket

Best Cooking Methods Summary

High-Heat Grilling:

1. Swordfish (best)
2. Tuna (excellent rare)
3. Salmon
4. Halibut (requires care)
5. Marlin (rare only)

Raw/Sashimi:

1. Tuna (bluefin ideal)
2. Salmon (sushi-grade)
3. Marlin
4. Never: Swordfish, halibut

Baking/Roasting:

1. Salmon (most popular method)
2. Halibut
3. Swordfish
4. Tuna
5. Marlin (less common)

Price and Availability Comparison

Most Affordable: Salmon ($12-22/pound for farmed; $18-30 wild)

Mid-Range:

• Swordfish ($18-30/pound)
• Tuna ($16-35/pound, varies by species)
• Halibut ($30-45/pound)

Premium/Limited:

• Marlin ($25-40+/pound, limited availability)
• Mako shark ($22-35/pound, rare)
• Sailfish (not typically sold)

Environmental and Sustainability Rankings

Best Choices (Seafood Watch):

1. Wild Alaskan salmon (most sustainable)
2. Swordfish (North Atlantic/Pacific) – recovered populations
3. U.S. Pacific halibut – well-managed

Good Alternatives:

1. Tuna (pole-caught skipjack/albacore) – depends on method
2. Marlin (Atlantic) – with conservation cautions

Avoid:

1. Mako shark – endangered globally
2. Bluefin tuna – severely overfished
3. Mediterranean swordfish – overfished
4. Imported halibut – varies by source

Which Fish Should You Choose?

For Regular Weekly Consumption

Winner: Salmon

• Lowest mercury
• Highest omega-3s
• Safe during pregnancy
• Can eat 2-3x weekly
• Widely available
• Multiple price points

For Grilling and BBQ

Winner: Swordfish

• Meaty texture holds up perfectly
• Doesn’t fall apart
• Great for kebabs
• Takes marinades well
• Creates impressive presentations

For Mild, Non-Fishy Taste

Winner: Halibut

• Most delicate flavor
• Pure white, flaky
• Appeals to fish skeptics
• Less fishy than swordfish

For Highest Protein

Winner: Tuna

• 25g protein per 3 oz
• Leanest option
• Multiple varieties available
• Excellent canned options

For Omega-3 Content

Winner: Salmon

• 1,921-2,260mg per serving
• Best heart health benefits
• Superior brain function support

For Pregnancy Safety

Winners: Salmon, Sardines, Skipjack Tuna

• All have very low mercury
• Recommended 2-3 servings weekly
• Avoid: Swordfish, marlin (occasionally), mako, sailfish

For Special Occasions

Winner: Swordfish or Prime Tuna

• Impressive presentations
• Restaurant-quality meals
• Memorable texture and flavor

Frequently Asked Questions

1. Which tastes better, swordfish or marlin?

Most people prefer swordfish for its richer, meatier flavor and fattier texture. Marlin is milder, leaner, and has a more delicate taste similar to tuna. Swordfish flesh is denser and more robust, while marlin is lighter with pink flesh that’s often described as having a subtle sweetness. However, blue marlin specifically has a fuller flavor closer to swordfish. The “better” taste is subjective—swordfish suits those wanting hearty, steaklike fish, while marlin appeals to those preferring lighter seafood.

2. Is swordfish healthier than tuna?

Tuna is generally healthier for regular consumption due to having nearly 3x less mercury (0.354-0.386 ppm vs 0.995 ppm). While swordfish provides more vitamin D (95% DV vs 6-40% DV) and similar omega-3s to albacore tuna, tuna offers more protein (25g vs 20-23g per 3 oz) and significantly more vitamin B12. The mercury difference is critical: adults can safely eat tuna 2-3 times weekly, while swordfish should be limited to once weekly maximum. Pregnant women can have limited tuna but must avoid swordfish completely.

3. Why is salmon better than swordfish?

Salmon is objectively better for health due to having 45 times less mercury (0.022 ppm vs 0.995 ppm), 2.5-3x more omega-3 fatty acids (1,921-2,260mg vs 764mg), and being safe during pregnancy. Adults can eat salmon 2-3 times weekly compared to once weekly for swordfish. Both provide excellent vitamin D and protein, but salmon’s dramatically lower mercury makes it the clear winner for cardiovascular health, brain function, and safe regular consumption. Swordfish’s only advantages are higher selenium content and firmer texture for grilling.

4. Can I substitute halibut for swordfish in recipes?

You can substitute halibut, but expect different results. Halibut has a more delicate, flaky texture that can fall apart during grilling or high-heat cooking where swordfish excels. Halibut works best as a swordfish substitute in gentler preparations like baking, poaching, or pan-frying. For grilling, use a fish basket or cedar plank to prevent halibut from breaking apart. The flavor difference is minimal (both mild), but texture differs significantly. Halibut is also 4x lower in mercury, making it a healthier choice despite being less suitable for certain cooking methods.

5. Which fish has the most mercury: swordfish, tuna, or marlin?

Swordfish has the highest average mercury at 0.995 ppm, followed by marlin at approximately 0.485 ppm, then tuna at 0.354-0.386 ppm (yellowfin and albacore). However, bigeye tuna can reach 0.689 ppm. Among commonly consumed fish, swordfish ranks as one of the top 5 highest-mercury species alongside shark, king mackerel, tilefish, and orange roughy. This mercury ranking directly determines safe consumption frequency: tuna 2-3x weekly, marlin 1-2x weekly, swordfish maximum once weekly for adults only.

6. Is mako shark the same as swordfish?

No, mako shark and swordfish are completely different species from different taxonomic classes. Mako is a true shark (cartilaginous skeleton, multiple gill slits, multiple rows of teeth) while swordfish is a bony fish with a flat, sword-like bill. However, their meat is remarkably similar in taste and texture—both mild, sweet, firm, and meaty. This similarity causes confusion in markets. The critical difference is conservation status: mako sharks are endangered and should be avoided, while swordfish from North Atlantic/Pacific waters are sustainably managed.

7. Can pregnant women eat any of these fish?

Pregnant women should completely avoid swordfish, mako shark, and sailfish due to high mercury levels. Marlin should also be avoided or limited to once monthly at most. Pregnant women CAN safely eat salmon (2-3 servings weekly recommended), skipjack tuna (2-3 servings weekly), and halibut (1 serving weekly). Albacore tuna should be limited to 6 oz weekly. The FDA explicitly recommends pregnant women consume 8-12 oz weekly of low-mercury fish for omega-3 benefits essential to fetal brain development, making salmon the ideal choice.

8. Which fish is best for grilling without falling apart?

Swordfish is the absolute best fish for grilling due to its dense, meaty texture that holds together perfectly even at high heat. It doesn’t flake apart, stays on skewers reliably, and develops excellent grill marks. Tuna (especially thick steaks seared rare) and salmon also grill well but require more care. Marlin can be grilled but must be cooked rare to prevent drying. Halibut is challenging to grill due to delicate texture—use a fish basket or cedar plank. For foolproof grilling, swordfish is the clear winner.

9. What’s the price difference between these fish?

From most to least expensive: Halibut ($30-45/lb) is priciest due to limited stocks and high demand. Marlin ($25-40+/lb) is expensive and rarely available commercially. Swordfish ($18-30/lb) is moderately priced with consistent availability. Tuna ($16-35/lb) varies widely—canned skipjack is cheapest while bluefin is extremely expensive. Salmon ($12-30/lb) has the widest range: farmed is most affordable ($12-18/lb), wild Alaskan runs $18-30/lb. For regular consumption on a budget, farmed salmon offers the best nutrition-to-cost ratio.

10. Which fish is most sustainable to eat regularly?

Wild Alaskan salmon (sockeye, coho, pink) is the most sustainable choice for regular consumption, with recovered populations, excellent management, and “Best Choice” Seafood Watch ratings. North Atlantic and Pacific swordfish are also sustainable (“Good Alternative”) after successful population recovery. U.S. Pacific halibut is well-managed. Skipjack and albacore tuna are sustainable when pole-caught. Avoid mako shark (endangered), bluefin tuna (overfished), Mediterranean swordfish (overfished), and imported halibut of unknown origin. Always check Seafood Watch ratings and choose certified sustainable options.

Conclusion

When comparing swordfish to marlin, tuna, salmon, and other popular fish, each species offers unique advantages. Swordfish excels in grilling versatility and meaty texture, making it ideal for special occasions despite high mercury levels requiring consumption limits. For regular weekly eating, salmon emerges as the clear winner with 45x less mercury, more omega-3s, and pregnancy safety. Tuna provides lean protein with moderate mercury. Halibut offers delicate flavor with 4x less mercury than swordfish. The best choice depends on your priorities: choose salmon for health, swordfish for grilling, tuna for protein, halibut for mild taste, and avoid mako shark entirely for conservation reasons.